(W180): Dados técnicos de remoção e instalação da embreagem
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(W180): Dados técnicos de remoção e instalação da embreagem
por AEP Qua 26 Mar 2014, 19:08
Fonte: http://www.mbzponton.org/valueadded/maintenance/clutch/clutch_replace.htm
Parte1:
Return to the Ponton Workshop page
Fonte: http://www.mbzponton.org/valueadded/maintenance/clutch/clutch_replace2.htm
Parte2:
Photo 2.
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Parte1:
Mercedes-Benz Ponton
Clutch Removal and Installation I
Jam Hamidi / sema@pacbell.net / California, USA
1959 Mercedes-Benz Type 220S
Clutch Removal and Installation I
Jam Hamidi / sema@pacbell.net / California, USA
1959 Mercedes-Benz Type 220S
Hello everyone,I just got back from the mandatory Memorial Day barbecue. We took the Ponton, and it was a blast. Up through the hilly Eldorado roads, everything green and lush because of all the rain we have had. In any case, here is my "clutch replacement saga" to share. The original problem was that the old Ponton could not go up hills anymore. The engine would just free rev. — a classic symptom of a slipping clutch. I tried adjusting it, but it was too far gone. The clutch replacement job took about five hours.
- Parts were purchased for about $450 from "Maria" of EMB Co. / Fairfax, Virginia / 1-800-881-4042.
- Jacking the car up on four stands for clearance: I bought four jack stands, the biggest I could find (up to 30 inches in height) and two jacks. One regular two-ton hydraulic, and the other a vertical hydraulic pump that goes from 10 to 18 inches. I used the regular one to raise the car enough to put the vertical one and a 4x6 piece of wood underneath. After a lot of huffing and puffing, I managed to install the four stands. I had a clearance of about 22 inches.
- I unhooked the negative of the battery.
- From underneath, I freed the two gear arms. The pins were difficult to pry, because there was not much light in there. One goes horizontally, the other vertically. I pushed them out of the way.
- I took out the clutch adjustment stuff, which is like a spoon coming into a oval nut, with a screw on each side and a spring to hold it. I took out the springs and the end hex screw, then pushed the oval thing down and freed the spoon. Then I undid the two hex nuts that held the arm of the longer screw and put everything away.
- I removed the speedometer cable, close to where the drive shaft meets the transmission. This took a while. It wasn't coming out at all, and since I didn't know if I should unscrew it, I proceeded with caution. There was one screw that needed to come off, then I used a flat screwdriver to widen the opening and pull the cable out, holding it with needle nose pliers. It came straight out.
- Disconnecting the drive shaft: I used the two jacks to take the weight off the engine (the regular jack with the 4x6 wood under the engine oil pan, the vertical one with another piece of wood under the transmission), not too much, just a bit. I marked down the alignment of the drive shaft and the central support bracket (but this proved useless, I forgot to check them later on). I took out the three bolts and nuts that held the shaft. I loosened them all a bit, then took them out and pushed back the shaft. It went back and up a bit. I jammed an old plastic flower pot to hold it up there, out of the way. I took out the middle metallic ring that looks like a rounded three-pointed star, then I unbolted the plastic connecting plate with the metal holes and washers.
- Taking out the transmission and the bell shaped clutch housing: I called my friend and neighbor Rudy to come and help with the rest, which proved to be an excellent idea. Most of the screws were in horrible places and it was great to have someone apply the pressure, while the other person held the wrench against the bolt, or to hold on a nut. First we tackled the starter, which is held by two long bolts, through the engine pass and bell housing. The two pairs of hands came in handy. We didn't unhook any of the wires going into the starter, just let it rest dangling by the wires on top of the engine. The two small bolts at the bottom were easy enough. They held a plate in front of the transmission, towards the front. The plate came undone. Then there were two more bolts on the left hand side of the bell housing. The top one proved hard because of its position. That was nothing compared to the two top bolts. I still have scratches everywhere trying to make my arms take unnatural angles in that small dark spot. The wrench with the elbow joint was the way to go. Most of the bolts and nuts were either 17mm or 19mm. With the exception of the two small ones at the bottom. Eight in total (two small on bottom, two per side, two on top). After all the bolts were out we tried jiggling the transmission out. It wouldn't budge. We ended up tapping it lightly with a piece of wood from where we took the starter out, and then jiggling it with both of us pulling. It finally came out — a big heavy thing. It was pushed out of the way.
- Taking the clutch out, and replacing the new parts: I ordered a new clutch, a new clutch pressure plate and throwout bearing. Apparently there are several different types of throwout bearings specified for the 1959 220S (at least according to my very kind supplier: "Maria" at EMB Co. / 1-800-881-4042) she sent me three various sizes and told me to send the ones I didn't use back. The clutch pressure plate is visible after taking the transmission and bell housing out. It was held with six bolts. We unscrewed them each a little since they are in tension, and took out the plate pretty easily. Rudy and I weren't prepared for the black cloud of petrified clutch dust that made us look like something exploded in our faces. The clutch was so far gone that all that remained was metal. Even the bolts were ground shiny. The bearing was held with two spring clips and it came out easily enough. The bearing was held against the metal pipe section. We hammered it out using a socket and a piece of wood, while placing it on two pieces of wood. The new bearing was put in place (I must say the old one didn't look that bad). Next we put in the new clutch plate, but we were at a loss how to center it. We tried with a piece of cylindrical wood, tapered down a bit, but finally it was just by sight as we bolted back the new pressure plate.
- Putting the transmission and bell housing back: I was waiting for this one because I read what you fellow Pontoners went through. We put the transmission back, but there was about ½ inch of distance. Too much for the bolts. I jiggled it while Rudy was rotating the clutch pressure plate and we had to do this for a couple of minutes until "click" it went in. I know we lucked out here. Taking it out was much harder than putting it together and bolting everything back. We screwed in the starter first, then the two bolts at the opposite side, then the top two (as usual, fun fun). Then Rudy took off to work on his boat. It seems he's always working on some engine. His wife is due to have their baby this Friday. Send her good vibes, they are a sweet family.
- Connecting everything back: It goes so much faster when you know where everything goes. The drive shaft, the clutch adjustment assembly, the shift arms, pretty much everything in opposite order from before. The only thing that was hard was the speedometer cable. It needed the flat screw driver again. It has a flat metal tongue that wants to go into the receiving slot. I felt with a screwdriver the direction of the slot and rotated the tongue accordingly, then I pried the opening with a screwdriver while pushing it in. It had to go in a precise amount for the screw to pass (less than half of the thick base sticking out).
- Clutch adjustment: I made it so that the clutch spoon was at the middle of the slit. I tried shifting to make sure it wasn't too tight, then I started the engine and checked out to see if the wheels turned at the right spot while pressing the clutch pedal. Everything seemed to go smooth.
- I lowered the car slowly, using my assortment of jacks, stands and wood pieces, then went up a little hill. Wow! Pretty good torque! No problems, and my little Ponton is all functional now. The work took from 8:00 a.m. until 1:00 p.m. Total cost of the parts was about $450. I took the kids to pick up hot dog buns and off to the barbecue we went!
- Jam / May 27, 2002
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Fonte: http://www.mbzponton.org/valueadded/maintenance/clutch/clutch_replace2.htm
Parte2:
Mercedes-Benz Ponton
Clutch Removal and Installation II
Andy Litkowiak / andylit@feralwombat.com / Illinois, USA / July 19, 2003
1959 Mercedes-Benz Type 220S sedan
Photo1.
Clutch Removal and Installation II
Andy Litkowiak / andylit@feralwombat.com / Illinois, USA / July 19, 2003
1959 Mercedes-Benz Type 220S sedan
Photo1.
This is the top view of the shift lever linkage box prior to beginning. This photo also shows a linkage section that the manual indicates should be removed, but I can see no reason to. That would be the rod and ball linkage on the left side that attaches to the horseshoe shaped transfer bar. I left it connected and had no difficulties.
Photo 2.
This shot is a more direct view of the two linkage points to be disconnected. These rods extend back to the transmission itself. They are easy to pry off. Just get some leverage with small pry bar or large screwdriver and pop them off. In this photo you can also see the two electrical contact terminals for your reverse light harness.
Photo 3.
Here are the two linkage bars disconnected. As stated earlier, these are very easy to pop off. The nylon ball housing is designed to be resilient and sturdy. This type of joint can handle quite a few removal/installation operations. This photo also offers a much clearer view of the reverse light terminals.
Photo 4.
The last activity on the top side involves removal of three bolts. The easiest is the top bolt for the starter. This also holds down the Negative battery cable and a grounding strap. Directly above the starter bolt on the bell housing side, you can see another bolt head. This is one of a pair of bolts that cannot be reached from the bottom. The twin is on the driver's side of the bell housing at the same height.
Photo 5.
This is the clutch linkage on the driver's side (US) of the bell housing. The flat bracket above the obvious linkage parts is a stabilizer intended keep the clutch linkage from banging around. This car has a completely mechanical clutch. No hydraulics at all.
Photo 6.
This photo shows a different angle of the clutch linkage. You will first detach the linkage from the throw out arm. On the upper stabilizer bracket, you can see one of the two nuts that hold the bracket to bell housing. You will remove these nuts next. Do not bother to pull the bracket apart. It, and the linkage, can be tied off to the side.
Please note that there are four main bell housing bolts visible in this shot. On the left vertical surface you have two large bolts. On the bottom of the housing you see two smaller bolts, one at the far right of the photo and one just above, and to the right, of the spring. These must also be removed.
Photo 7. Once you remove the linkage stabilizer, you will find a number of shims sitting on the studs.
Do not lose these little fellows.
Do not lose these little fellows.
Photo 8. Close-up of the linkage stabilizer shims on the studs
Photo 9.
Before you go any further, be sure to detach the drive shaft at the rear of the transmission. You need to pop out three bolts with cotter pins. I chose to do the rearmost, although I am not sure if it matters.
Photo 10.
After you have detached the shaft from the rear of the transmission, you will detach the center shaft carrier. Locate the cover plate midway to the rear of the shaft tunnel. The center bolt holds the cover and the two bolts on the sides hold the shaft carrier in place.
Photo 11.
Do not worry about marking the location. This will self-locate during re-installation (provided you do things in order).
Photo 12.
Once you have detached the center carrier, you can push the drive shaft back out of the way. You do not need much clearance. Please note that you do NOT have to detach the shaft at the differential. The expansion fitting at the rear of the shaft has enough travel to allow the trans to drop.
Photo 13.
The casualty in this photo is my speedometer cable. The cable must be removed from the transmission before you drop it. The nut visible next to the cable is loosened and the cable is withdrawn. In my case, the cable sheath has come loose from the end housing. This is almost certainly the cause of the speedometer jumping and hopping I get on occasion. To correct this for the short run, I opened up the end housing with a small flat screwdriver and re-inserted the sheath. I then secured it in place with a very small hose clamp. The end housing is a thin aluminum crush fitting. This should hold me until I get a new cable.
Photo 14.
This is a shot of the right side of the bell housing. Before you pull the last two bolts, you must remove the exhaust hanger support. First, you pop off the two small nuts visible in the photo. Then you remove the third bolt to the right of the bolts visible in this shot. Once you pull the third bolt, the support will come out, leaving you the steel "tab" attached to the transmission.
A word to the wise: If you think it is too tough to get that third bolt, think again. It is even tougher getting the transmission past that support bracket. I know, I tried it.
Another word to the wise: The idea may cross your mind that it would be easier to remove the transmission, then remove the bell housing. Wrong again. The transmission is attached with nuts and bolts. Those are not studs.
Photo 15.
Then, a miracle occurred and the transmission appeared on the floor. Sorry, no photos of that phase. It was too tough to shoot while we pulled it. You will need a floor jack (if you are on the ground) or a transmission jack. I strongly suggest two men for this job. The transmission is not too heavy, but it is a little awkward.
Removal consists of tapping the transmission backwards while the other guy holds it to be sure it does not drop. Mine came out fairly easily because of all the oil that had been spewing out of the engine over the years. I did not have a single stuck bolt.
You might experience some resistance if you have a dry motor and components. The most common hang up is that the transmission shaft hangs up on the clutch splines, the pilot bearing, or both. Persevere. A big rubber mallet is usually adequate to pull a stubborn transmission shaft.
You will do a bit of wiggling and shifting to get the entire unit clear. It is a little tight up there, but you can get it out.
Photo 16.
This is the throw out bearing and the clutch fork. Do not inspect the bearing. ALWAYS replace the bearing when doing the clutch.
Before you pull the bearing, make careful note of the fork spring locations. Pull the springs before you pull the bearing. Do not lose them, your auto parts store probably does not carry this particular spring.
You will most likely need a puller for the bearing. Most auto parts store will rent or lend you one if you do not have one. I suggest buying a puller. They are very handy and usually required about 5 minutes after the parts store closes.
I will also suggest that you purchase the entire bearing assembly from Mercedes-Benz. You can just buy the bearing, but the bearing collars do wear over time. Why put a worn collar into a new bearing?
Photo 17.
There it is, the mother lode. This is what it is all about. The clutch. You will note the six bolts holding this in. You should pull these out criss-cross. Do not just work your way around the clock.
As you loosen these bolts, be very careful. The clutch is under pressure. At some point in the operation, before the last bolt is out, the outer plate is going to pop out a half inch or so. If your finger tip or knuckle is close enough, you could actually break a bone. At best, it will sting like hell.Photo 18.Once you have removed the clutch pressure plate and disc, this is what you will find. In this shot, the flywheel has already been cut. You will remove the 6 stretch screws to pull the flywheel. I suggest using an impact tool to remove them. Be careful when you pull the last screw. The flywheel is pretty heavy. If it falls, you could chip a tooth (yours or the car's).Photo 19.Once the flywheel is out, you will encounter the pilot bearing cover. I forgot to shoot photos coming out, so we are stuck with the install photo. The cover is pried or pulled out. Behind this cover is the pilot bearing (sorry, no photo). I strongly recommend that you replace this bearing as well. Yours may be okay. Great. Clean it, oil it and put it on the shelf. I am a big believer in renewing wear parts when you are in a spot you will not be looking at again for a long time. You may as well have all the parts be the same age. To pull the cover and the bearing, I jury-rigged a puller. I took one arm from a small gear puller and clamped a pair of vice-grips to the opposite end of the arm. Insert puller arm, tap the pliers with a hammer. I do not have a slide puller (top of the to-buy list now).Photo 20.Here is your flywheel after you have had it cut. In this photo, you can see that the parts shop machinist turned both the friction surface and the mounting surface (see arrow). At first, I wondered if this was correct. The difference between the mounting surface and friction surface must be maintained to spec. If you are taking a significant cut off the friction face you probably need to cut the mounting face too. So the machinist was correct to also cut the mounting surface.Photo 21.Here is the flywheel back in again. Torque the screws to about 30-35 pound-feet. Use a torque wrench. Do not do this by touch. Be sure to clean the flywheel after installation. I suggest brake cleaner. It must be totally free of any grease, oil or dirt. In order to lock the flywheel while torqueing the screws, I used a very short medium sized flat screwdriver. I just lodged the tip between two teeth and set the base against the lower left motor mount. It worked perfectly.Photo 22.Here is your new clutch. Please note the clutch tool. I would suggest you get one. It will make the installation go much smoother. I happened to have a tool from my Toyota Land Cruiser days. Luckily, it was a perfect fit.The Toyota tool is available at: this link. If the link is dead, go to www.sor.com (Specter Off-Road, Inc.) and search for item # 200-11 (as of July 20, 2003). The tool is $8 and shipping will probably be about that much. I have not researched the Mercedes version of the tool.Photo 23.As with the flywheel, be sure to clean the clutch plate pressure surface with brake cleaner. Do not clean the disc.Photo 24.Here is your clutch tool in action. This little beauty slides into the disc splines and then seats in the pilot bearing. It holds the disc in perfect alignment as you install the pressure plate.Photo 25.Here is your new clutch, ready to accept the transmission and bell housing. To go forward from here, just follow the earlier steps in reverse. It is pretty straight forward. To adjust your clutch, simply run the mechanical linkage out to the end and start working your way in until it catches. Begin testing where the pedal engages until you have a nice smooth engagement.Photo 26.And finally, a word about safety to all. Always wear eye protection when working on your car. You never know what my break, move, slip or just plain fly off the car. All it takes is a little glob of gritty grease plopped into your eye and you are spending the rest of the day in the emergency room.- Andy Litkowiak / July 19, 2003
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Última edição por AEP em Sex 15 Abr 2016, 15:52, editado 1 vez(es)
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Re: (W180): Dados técnicos de remoção e instalação da embreagem
por AEP Qua 26 Mar 2014, 19:09
Parte3:
The clutch in my 1959 Type 220S cabriolet was slipping badly, especially under load. I heard or felt no other symptoms like noise or grinding of gears. I decided that a new clutch was in order. Never having done a clutch job before, I contemplated the enterprise with trepidation. I read the service manuals, which are straightforward in the clutch and transmission sections. I consulted the articles written by ponton owners:
After finishing the job, I felt an article coming on, susceptible that I be to periodic bouts of authoritis. There is but one cure. Read on. My write-up will not repeat material in the above pieces, but it will serve as a supplement providing additional information. Note that the Hydrak clutch is not discussed. Also note that it does not address the differences in the mechanical clutch for the 220SE ponton, particularly with respect to the driven disk, the pressure plate, and the release bearing and sleeve.
Appearance
After disassembling the clutch, I found that the clutch disk was worn into the rivets on the pressure plate side. The pressure plate was scored. Sometimes pressure plates can be resurfaced, but I opted to get a new one anyway. Some friction material remained on the flywheel side of the disk.
Pilot Bearing (a.k.a. [1] clutch spigot bearing)
The small pilot bearing fits inside the end of the crankshaft. The original pilot bearings were open on both sides and packed with grease. The grease on mine had caked, and the bearing turned roughly and noisily.
There is a small metal cover that must be pried out. In doing so the cover may become bent at its hole. Lightly hammer it back flat. Normally a pilot bearing removal tool is used to extract the bearing. I borrowed one.
Always replace the pilot bearing. It is cheap: Mercedes list price $33.00, part number 115-980-01-15. The pilot bearing is an industry standard [1a] bearing number 6202. [2] I bought an SKF 6202 (DIN 625) bearing from my local bearing supplier. Cost: $5.50. Under this industry number one can get an open or sealed bearing. I chose to get a sealed one. Now I need not concern myself that the bearing will become dry or that I greased it incorrectly. It fit perfectly. Tap it in with a socket after lightly oiling the outside and the receptacle cavity.
Flex Disk (a.k.a. shaft plate and "guibo")
The flex disk is the hexagonal rubber item between the transmission and the propeller shaft. Because it must be removed to lower the transmission, I decided to replace it even though it did not appear seriously degraded. Mercedes part number 180-411-06-15; list price $99.00. These are the same on all pontons since mid-1956. [3] They are available through aftermarket suppliers for much cheaper than the Mercedes price. I paid $53.00 for one manufactured by Jurid, the manufacturer of the ones sold by Mercedes. [4]
If not damaged, the six bolts and nine washers can be reused. Originally they were locked by castle nuts and cotter pins although sometime nylok stop nuts are present as previous replacements. The castle nuts are available from Mercedes: list $6.75, part number 183-990-00-55. Places that supply metric nuts and bolts can order them. Size M12, 1.5 pitch.
Before removing these bolts, washers, and nuts, note carefully how they are fitted. Make a diagram. Look carefully at the 190 service manual figures 41- 1/5 and 41-4/1. Note that the three slightly longer bolts (with a knurl on the head) connect the flange on the transmission side with the flex disk. The nuts face the transmission.
The three slightly shorter bolts (conventional hex head) have two washers each. These washers abut both sides of the flex disk. See items 11 in figures 41-1/5 and 41-4/3. Again, the nuts face the transmission.
Finally, be sure to note the correct orientation of the flex disk as shown in the 190 service manual at figure 41-1/4a. The side with the lips/eyebrows over the holes faces the transmission, and those holes fasten to the transmission flange. The long bolts go through the flex disk holes with the lips and fasten the flange on the transmission side.
Release Bearing and Bearing Carrier
This topic was more troublesome to sort out than I expected, but it led to interesting discoveries. For this reason I have laid out what I have learned in considerable detail so the information can be preserved. Some aspects may seem historical and anachronistic, but there is significant potential for confusion when looking for the correct bearing. I have divided this section into discussions of the release bearing itself and the sleeve on which the bearing is carried. Refer to the following photos[5] when reading this section:
(A) Bearing Sleeve/Carrier/Body [6]
Apparently Mercedes has never supplied the sleeve as a separate item with a unique part number. If someone needed a new sleeve from Mercedes, the only option was, and is, to buy the sleeve in combination with the bearing. The original part number for this combo was 121-250-01-15. It included the "old type" sleeve and the "old type" release bearing. That combo is no longer available from Mercedes. What that means is that Mercedes no longer supplies the "old type" sleeve. As discussed below, if an "old type" sleeve is present and in reusable condition, the release bearing appropriate to it is available from Mercedes and, quite limited, in the SKF and FAG bearing vendor aftermarket.
If the sleeve is undamaged, it can be reused. Some people, however, prefer to replace the bearing and sleeve with new ones, to be on the safe side. The "new" bearing-and-sleeve combo Mercedes currently supplies is part number 110-250-00- 15; list price $170.00. This part number supersedes the original 121-250-01-15 number for the "old" combo that is no longer supplied.
At some point after the ponton era Mercedes changed to supplying only the "new type" sleeve. That sleeve requires the "new type" release bearing. If a new sleeve is required, the "new type" is what you will get from Mercedes, but only as part of the "new" combo.
The inside of the sleeve has a small depression. Dab some grease there to keep the sleeve from binding when sliding over the shaft during operation. At the same time lightly grease the splines on the input shaft of the transmission.
(B) Release Bearing (a.k.a. throwout bearing and clutch withdrawal bearing)
Once the transmission is out, the release-bearing-and-sleeve combo is easily removed. Note carefully which side of the old bearing faces the ears of the sleeve. The bearings can be positioned on the sleeve either way, but only one way is correct. The bearing I removed and its new replacement had serrations around the outside edge of the bearing on the side facing away from the sleeve ears. Also the serrated side is the more beveled outer perimeter of the bearing.
I elected to reuse the sleeve as it was undamaged. To remove the old bearing I used a Dremel-type tool with a cutoff wheel. With care, patience, and a steady hand this works fine. Alert: Wear eye protection!
The new release bearing is a press fit onto the sleeve. I put the sleeve in the freezer and heated the new bearing in an electric skillet to maybe 300 degrees (F). When I was ready to assemble the two, I squirted some WD-40 on the sleeve and verified, yet again, the correct orientation of the bearing. Then it slipped right on.
(B.1) New Bearing - M-B part 000-981-43-25
Mercedes lists $85.00 for the "new type" bearing alone; part number 000-981-43- 25. Note this is a sealed ball bearing. The one I bought in a Mercedes box was made by SKF and carried the SKF number 360540. This is not an industry standard bearing, so it is not available generically. Its published dimensions (in millimeters) are:
40.0 inside diameter
69.6 outside diameter
20.5 width
SKF still lists this number as valid. Apparently SKF produces it in batches on demand. Existing stock can be found outside of Mercedes channels. When I was looking for this SKF bearing before I did the work, I received quotes ranging from $65.00 to $135.00 plus shipping. Researching this article, however, has led me to a private American source of these bearings for nearly $50.00 plus shipping. Would that I had done my homework better!
As to equivalents, FAG 526814 B was a direct equivalent to SKF360540. The dimensions are identical, and it appears on the SKF cross-reference list. Apparently this FAG number remains good but only as original equipment, according to FAG. I may have found a private source for this bearing at nearly $50.00. FAG technical data lists this bearing as equivalent to Mercedes bearings as follows: [7]
981-143-25-?? [8]
001-981-52-25 [9]
504-620-90-04 [10]
110-250-00-15 [11]
(B.2) Old Bearing - M-B part 121-254-00-10
Mercedes still supplies the "old type" release bearing: part number 121-254-00-10; list $147.00. I cannot testify as to its SKF number as I have not personally seen this bearing. I suspect it is the SKF 306654 B that Hkan found (see following), but I am not certain.
One member of the International Ponton Owners Group (IPOG), Hkan Johansson, reports that he removed a release bearing from his 219 with SKF number 306654 B on it. SKF reports that this bearing is obsolete and discontinued. The dimensions (in millimeters) of SKF 306654 B are:
40.0 inside diameter
69.0 outside diameter
21.0 width
I may have unearthed some of these bearings from a private source also. The price may be nearly $50.00 plus shipping.
I came across reference to another discontinued FAG bearing, FAG 501929 C. Its dimensions (in millimeters) are:
40.0 inside diameter
69.2 outside diameter
21.5 width
FAG technical data cross reference this bearing to SKF 306654 B. I found a small stock of this FAG 501929 C bearing in the USA from a private source and from Werner Karasch in Germany but nowhere else. [12]
One more relevant FAG bearing came to light: FAG 505310 C. It was identified as being for the "early type" ponton release bearing. I was unable to obtain any dimensions as it is totally obsolete. I cannot compare and contrast it with the other FAG bearing, FAG 501929 C, indicated above as being suitable as the "early type" release bearing.
(B.3) Other Manufacturers
I came across no indication of manufacturers other than SKF or FAG ever making the release bearing for pontons. This research effort led me to speculate that SKF and FAG made the above release bearings only for selected Mercedes and Fiat applications.
(C) Conclusion
The mention by o amigo Alexander, a member of the International Ponton Owners Group (IPOG), of an "early" and "late" release bearing is now clarified. Clearly the "early" type was SKF 306654 B and FAG equivalent, and the "late" type was SKF 306650 and FAG equivalent. Different sleeves were used "early" vis--vis is "late." They must not be interchanged. What this means is that if you locate a new "early-type" bearing, SKF 306654 B or FAG equivalent, you must reuse your "early type" sleeve or find another identical sleeve. Otherwise you must obtain a "late type" sleeve and an SKF 360540 or equivalent FAG bearing. Early-type sleeves cannot be mixed with late-type sleeves and vice versa. I do not know when "early" changed to "late" with respect to any of the ponton models, but I have come to believe it happened after the end of the ponton era. [13]
Confused? I certainly was until I came to realize that the sleeve was never supplied separately and never had its own part number. Now consider yourself informed about that as well as the different bearings.
Driven Disk
The 200-mm clutch disk is now Mercedes part number 010-250-12-03 for all pontons that use the dished-type flywheel. Mercedes list price is $252.00. It is made by Sachs and carries the Sachs number 1861-123-236. It is available much less expensively from aftermarket vendors. I paid $85.00.
The only thing to emphasize here is the correct orientation when installing it. One side is marked getreibe seite. Be sure to position that side towards the pressure plate and the transmission.
Pressure Plate (a.k.a. clutch plate)
The pressure plate for all pontons with the dished-type flywheel is now Mercedes part number180-250-07-04. List price $242.00. This too is made by Sachs, Sachs number 1882-102-132. Widely available in the aftermarket, I paid $106.00.
Sometimes removing the old pressure plate can pose problems. Other times it backs out easily after loosening the screws slowly and gradually, using a cross pattern. In my case it was quite stuck in place. I tapped all around the outside and pulled on it. I squirted penetrant around the beveled edge (I found the seam after removing all the dust and dirt). Still no give. Finally, I used a crow-foot pry bar in the hole where the disk is visible and slowly jiggled it off. All the while I had concern that I might damage the flywheel somehow. No problems.
When installing the pressure plate, be sure to tighten the six screws evenly, using a cross pattern of tightening. I chose to turn each screw one turn, one after the other. You may have to press the plate in with your hand to get the screws started. Tighten to the prescribed torque value. (See separate discussion below of screws and torque values.)
When tightening the pressure plate, the "fingers" will raise slightly from the plate. Pieces looking like large staples should fall out from between the plate and the fingers if you have not previously found and removed them. If they do not, do so now. These are for shipping the pressure plate, not for the system's operation.
The service manual specifies that, depending on the model, there should be a specific distance between the end of the finger and the pressure plate. The specified differences among ponton models is very small. See the 190 service manual at section 25-1/3 and the 180-220S/SE service manual at section 25-1. To adjust this distance one turns the nuts on the bottom of the "fingers." I could not figure out how to obtain a precise measurement while the flywheel was still in the car. Access was too awkward. This procedure, if necessary, is doubtless doable with the engine and flywheel removed from the car. Based on advice I received, I decided to leave the nuts untouched and let any small deviation from specification be handled via the clutch adjustment later.
Flywheel
To do or not to do, that is the question. As a matter of routine, should one remove the flywheel to have it resurfaced? Of course, if its face is obviously scored, this will be necessary as long as "turning" does take it beyond specifications set forth in the service manual. If there is no obvious scoring or other damage, or if the blemishes are very minor, the question of prophylactic resurfacing arises. After all, at this point you have easy access to it. People come down energetically on both sides of the question.
First of all, the flywheel inside and outside is very likely to be dirty and crudded. It needs to be thoroughly cleaned before you can make a determination about resurfacing. I squirted a lot of brake cleaner spray and cleaned off as much crud as would come. Most did. Dried it with paper towels. Then I used WD-40 and 0000-guage steel wool to remove any traces of minor rust and dirt on the face. Then it got carburetor spray treatment and towel cleanup again. Finally, I cleaned off the face and inside side of the cup with PVC plastic pipe cleaner, a liquid cleaner that dries immediately. (This is what is used to clean PVC pipes for gluing.) That flywheel ended up spotless!
Then I examined the flywheel for cracks, other signs of metal fatigue, and grooves. I gave it the thumbnail-scrape test. It was very smooth.
I concluded that the flywheel's condition did not compel resurfacing. Should I resurface it anyway simply because it is now accessible? There was no escaping the question. I finally came down on the side of those who say "if it is not broken, don't fix it." Resurfacing necessarily shortens the life of the flywheel and may weaken it slightly because the process removes metal. Many professionals report they do not routinely resurface flywheels and in fact seldom do so unless the need is obvious.
In the end my reasoning was that every task includes the possibility of error, damage or injury, no matter how careful one may be. Removing the flywheel carries a certain, albeit minor, risk. Giving it to a machinist for resurfacing involves the possibility of loss, mistake, or damage. I could mess up the reinstallation (been there, done that). I could injure myself. In light of the excellent appearance of the flywheel, I weighed the risks involved in resurfacing it. The scales tipped towards leaving things alone. Of course, all this is a personal judgment.
Here I offer an observation. On some cars (not pontons) removing the flywheel provides convenient access to the rear crankshaft seal. Some people want to replace this as a precaution. Sometimes the seal is leaking, so one wants to have access to it. Stand down! Apparently that seal on pontons cannot be reached for replacement simply by removing the flywheel. Generally the engine must be removed and partially disassembled to replace that seal. So if that seal is leaking, the flywheel is not a facile route to it.
Transmission Removal and Reinstallation
Here, I speak only to removing the transmission from beneath the car while the car is on jack stands; that is, for us home garage duffers. My hydraulic floor jack would not lift the car from the front high enough to provide sufficient clearance either to work at the transmission or to drag it out from under the car once it was on the floor. I had to raise the front of the car higher than the jack would go. What to do?
For starters, I activated the emergency brake and put chocks behind the rear wheels to keep the car from rolling backwards. Anticipate safety needs first and always!
Then I placed the hydraulic jack, with a short 2 x 4 wood piece on the lifting plate, under one side's rockers, just forward of the front jack points where the rocker turns towards the engine. Then I raised the jack about two-thirds of its extension. Next I placed a jack stand, also using a similar piece of wood as buffer, under the rocker at about the jack point and extended it. Then I repeated the process on the other side except that I raised the jack to full extension, which resulted in raising the jack stand to near its maximum height. I returned to the first side and raised the jack stand to nearly full extension, using the same jacking process. The reason I lifted the car in stages is that I did not want to twist the body too much. I do not know if this is could be a problem, but I would not risk anything.
This jacking procedure provided ample clearance. The transmission was moved readily from under the car and back. I had plenty of room for access.
Does one need a special transmission jack or transmission adapter for a floor jack? Doubtless it is easier to raise and lower the transmission with such a device than with a regular hydraulic floor jack or with two retirees on their backs struggling with it manually. (I weighed the transmission and bell housing; it weighs 70 pounds/32 kilos.) I used my floor jack and kept a careful hand on it, maneuvering the transmission around. A cloth on the lift plate of the jack reduced slipping around by the transmission. A helper worked the jack handle in response to my commands when I was under the car. Admittedly the transmission came out this way easier than it went back in, but in the end the procedure worked satisfactorily. In sum, using a hydraulic floor jack without any special transmission lifting device is certainly a viable option.
Once the transmission was out, I cleaned its exterior. Inside and outside the bell housing was also cleaned. Everything was very dirty and greasy.
Examine the transmission for leaks. Finding none on mine, I did nothing further to it. I did not disturb the shift levers, one on the top and one on the side. Mechanically the transmission operated properly before I removed it. Know that if you turn the transmission over far enough, fluid will leak out the vent on the top. This vent is beneath a bell-shaped brass cover. I removed the vent and cleaned the screen.
Be careful examining the transmission. You do not want to bend the shift rods or levers. Also, note carefully which rod goes where; they are shaped differently.
Lever the shift fork off the pivot ball. Do not lose the locking ring in the socket. Clean and grease everything. Reinstall.
Replacement items
I decided to replace every rubber bit associated with the entire enterprise plus a few other things. That included the two round rubber bushings [14] where the shift levers fit to the shift rods on the transmission.
For this discussion note the following illustrations from the Type 220S spare parts book [15], Catalogue "C," dated 1958. Illustrated spare parts books for other pontons will have comparable pages.
The brake control rod fits into a bracket (item 25), specifically into something resembling a thick wedding ring, item 46 (do not lose this ring: 186-991-00-29, list $33.50). Inside that ring is a needle cage, item 45. I replaced it, part number 000-98-18-10, as it was destroyed; list price $19.50. The "wedding ring" is stabilized inside item 25 by a small spring plate (sometimes shown in parts depictions as item 47a and other times not shown but required nevertheless); 121-993-00-26, list $19.50. Be sure you have the correct washer, item 44; Mercedes 000-988-010-016, list $1.00. This washer is DIN standard 10 x 16 x 1.
Look at the rubber pieces that fit between the brake and clutch pedal rods (item 55) and the firewall on the engine side. They are probably mush or even nonexistent by now. I replaced mine on each pedal; they are identical. Mercedes number 120-291-03-97, list $4.00. I also replaced the washers, item 54. Part number 136-224-01-66; list price $2.00. This replacement allowed me to be certain I would obtain the correct clutch adjustment as it keys off the brake pedal as prescribed in the service manual.
Note item 57 (Mercedes number 136-290-00-67) where the pedals are depicted. It is misleading. This is a leather piece riveted to a metal piece. It fits inside a plate around the pedal rods on the driver side of the firewall. At $49.00 list price each, I chose not to replace them.
You may have to fabricate the gaskets on item 42, cover plate. I did.
Note a threaded hole about two-thirds of the way towards the top on the left side of the bell housing. It takes a washer and an air bleed screw, items 34 and 35. This screw is some kind of venting device because it has a tube extending from the bottom of the shaft to inside the head where it branches to the opposite head flats. Don't simply plug the hole with a regular screw. A new bleeding screw, part number120-251-00-71, lists at $29.50. Frankly, I did not understand why this air bleed is necessary as air seemingly enters the bell housing from other places.
Not shown on any of the above illustrations is the rubber bushing that fits between the transmission and drive shaft flanges. It is part number 120-411-00-60; list $2.20. I replaced it.
Reverse Light Switch
Probably the wire harness will be cracked and oil-soaked. I fabricated a new one. See for the general approach:
http://www.mbzponton.org/valueadded/technical/harness.htm
The original harness was 26 inches/66 centimeters long. I recall using12-gage stranded wire.
The rubber boot (number 98 in the illustration) covering the brass switch where the reverse light wires connect is part number 000-546-00-35; list price $5.00. And no, it is not identical to the boots on the generator and coil.
Note that there should be a rubber boot covering where the positive battery cable connects to the starter solenoid. This boot is identical to the one that fits over the reverse light switch on the transmission.
Torque Requirements
My flywheel was fastened by screws that had the marking 12.9 on them. That meant they were highly hardened in metric terms. As I did not remove the flywheel, I did not disturb them.
Considerable discussion developed as to the correct torque value for the flywheel screws, and it became almost esoteric. Opinions varied as to the correct torque. Then, as he was proof reading the final article, Jeff Miller referenced the "Mercedes-Benz Technical Data Passenger Cars" (December 1957 Edition, page 123) and found the flywheel tightening torques to be listed as follows: 6-6.5 mkg [16] for the Types 180a, 190 and 190SL. The Types 219, 220a and 220S have a tightening torque of 4.5-5 mkg.
I found myself concerned with the six screws that fixed the pressure plate to the flywheel, item 19 in Table 12 above. The screws I removed were marked "8G." This was the hardening indicator. It is not the current metric hardening numbering system, so I was confused about how much torque to apply when reinstalling the screws. Again much discussion ensued, which I initiated. Hkan Johanssen and Jim Davis were instrumental in clearing up confusion. The conclusion is that the"8G" screw I removed meant today's 8.8 metric hardening. See:
Before this got resolved, I decided to get new screws. The new screws, Mercedes number 304-017-008-048 (list price $1.40), came with a hardening mark of 10.9. This suggests Mercedes increased the torque value for this application. Search as I did, nowhere did I find any authoritative Mercedes document specifying the correct torque for these screws. Web sites indicating the torque for untreated M8 screws with a 10.9 hardening value ranged between about 25 lb. ft. and 36 lb.ft. See the following sites and take your pick:
I put a touch of antiseize lubricant on the bottom threads of each screw and went to 35 lb. ft. torque. Nothing snapped.
The pressure plate screws presented another, more or less academic, curiosity. The Mercedes parts manual lists M8x28 DIN 931 and then M8x20 DIN 933 as replacement. The former is slightly longer and has threads part way up the shank. The latter is slightly shorter and has screw threads all the way to the head. Was this significant? Did this change mean that something else had changed along with this different screw? Something expensive? Perhaps nothing more than a bulk-purchasing convenience? I don't know, but I don't think so. The difference in length is eight millimeters. The screws I removed and the ones I bought were of the subsequent M8x20 DIN 933 designation although, as noted above, the hardening mark differed.
Disclaimer: The author has provided accurate information based on his research and personal experience. Use the information at your own risk. Verify it to your own satisfaction. No guaranteed is implied or warranted.
Request: Suggestions for additions and corrections are welcome.
Thanks: Particular thanks go to Jeff Miller, the curator-editor of the Mercedes-Benz Ponton web site. As usual, he labored mightily to transform this document into a usable web page. Len Sokoloff provided the scans from the Type 220S picture parts book. o amigo Alexander, Jim Davis, and Henry Magno provided prepublication peer review which was indispensable. They are not responsible for any errors.
Footnotes
[1] a.k.a. = also known as.
[1a] "Industry standard" refers to bearings that have specified characteristics and tolerances that meet established industry norms. Any bearing manufacturer would have to meet those norms. Therefore, any bearing marked with the 6202 number, whether made by SKF, FAG, or other, would meet those norms for the 6202 and would be interchangeable one with another. Mercedes and other auto makers use such bearings, often in several applications within the same vehicle and on different models. The same happens with oil and grease seals. On rare occasions, however, seals and bearings are unique to a specific vehicle application. They are still available in the bearing market, but sometimes not at such a great cost percentage savings as with industry standard items.
[2] Interesting to note that the 6202 standard bearing fits the following additional applications on pontons: (1) 180b and 180D (1956-58) - fan front and rear, water pump, injection pump drive (180D only); (2) 180a, 190, 190D, 190SL, 220a, 220S (1956-59) - water pump; (3) 180b, 180DC, 180c, 180Dc water pump rear, fan pulley front and rear, injection pump drive. Apparently the 220SE did not use the 6202 bearing anywhere, or the literature simply failed to mention the 220SE, or the 220SE was discussed on a page I did not receive.
[3] For details see section 41-4/1 of the 180220S/SE service manual.
[4] Thierry Savidan reports he bought a new one in Thailand for US$10.00.
[5] Courtesy of o amigo Alexander.
[6] Sometimes called the release bearing carrier. Confusion may arise when dealing with German suppliers and German translations. Sometimes the German, when discussion this item in English, refers to it as "release bearing" because it "bears" the ball bearing (which in English we call "release bearing"). Until I realized what was happening, this caused me not a small amount of confusion when communicating with native German speakers. For native English speakers the "release bearing" is the special sealed ball bearing. For the German "release bearing" can refer to what we call the sleeve or carrier.
[7] FAG technical data also list this bearing as equivalent to SKF 616524 and SKF 616524 A which SKF reports to be obsolete and discontinued. These bearings had the following dimensions (in mm): 40.0 inside diameter, 70.0 outside diameter, 18.0 width. This is extremely close to the dimensions of SKF 306540 and the discontinued SKF 306654 B.
[8] This number is obviously screwy. It does carry the 981 number which is Mercedes-Benz speak for bearings.
[9] Mercedes-Benz reports that this number has been supersedes by 000-981-43-02. This is their current bearing number for the pontons and is SKF 360540. Note the 981 bearing series number.
[10] No longer a valid number.
[11] Note, this is the same number M-B currently uses for the "new type" combo.
[12] Karasch offers FAG 501929 C for 74.00 plus shipping.
[13] Just to confuse matters, courtesy of Hken Johansson I have a copy of an SKF product sheet for the ponton range. It lists SKF 306564 B as the clutch release bearing for all ponton models, except the 220SE, for the duration of their production. Thus I cannot say for certain when the SKF 306540, with its slightly different dimensions and with its requirement for a different sleeve, came into use. But come into use it did, and M-B now supplies it for the ponton clutch release bearing application.
[14] My 180-series transmission wore a Type W111 "Fintail" series cover. This combination works fine. I assume this happened when my car was converted from Hydrak during the 1960s. The rubber bushings are different, so I am not providing the part number.
[15] Courtesy of Len Sokoloff.
[16] 1 mkg (kilogram-meter) = 7.233 ft-lbs.
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Mercedes-Benz Ponton
Clutch Removal and Installation III
By Douglas P. Broome / douglas.broome@verizon.net / January 17, 2003
Clutch Removal and Installation III
By Douglas P. Broome / douglas.broome@verizon.net / January 17, 2003
The clutch in my 1959 Type 220S cabriolet was slipping badly, especially under load. I heard or felt no other symptoms like noise or grinding of gears. I decided that a new clutch was in order. Never having done a clutch job before, I contemplated the enterprise with trepidation. I read the service manuals, which are straightforward in the clutch and transmission sections. I consulted the articles written by ponton owners:
- http://www.mbzponton.org/valueadded/maintenance/clutch/clutch_adjust.htm
- http://www.mbzponton.org/valueadded/maintenance/clutch/clutch_replace.htm
- http://www.mbzponton.org/valueadded/maintenance/clutch/clutch_replace2.htm
After finishing the job, I felt an article coming on, susceptible that I be to periodic bouts of authoritis. There is but one cure. Read on. My write-up will not repeat material in the above pieces, but it will serve as a supplement providing additional information. Note that the Hydrak clutch is not discussed. Also note that it does not address the differences in the mechanical clutch for the 220SE ponton, particularly with respect to the driven disk, the pressure plate, and the release bearing and sleeve.
Appearance
After disassembling the clutch, I found that the clutch disk was worn into the rivets on the pressure plate side. The pressure plate was scored. Sometimes pressure plates can be resurfaced, but I opted to get a new one anyway. Some friction material remained on the flywheel side of the disk.
Pilot Bearing (a.k.a. [1] clutch spigot bearing)
The small pilot bearing fits inside the end of the crankshaft. The original pilot bearings were open on both sides and packed with grease. The grease on mine had caked, and the bearing turned roughly and noisily.
There is a small metal cover that must be pried out. In doing so the cover may become bent at its hole. Lightly hammer it back flat. Normally a pilot bearing removal tool is used to extract the bearing. I borrowed one.
Always replace the pilot bearing. It is cheap: Mercedes list price $33.00, part number 115-980-01-15. The pilot bearing is an industry standard [1a] bearing number 6202. [2] I bought an SKF 6202 (DIN 625) bearing from my local bearing supplier. Cost: $5.50. Under this industry number one can get an open or sealed bearing. I chose to get a sealed one. Now I need not concern myself that the bearing will become dry or that I greased it incorrectly. It fit perfectly. Tap it in with a socket after lightly oiling the outside and the receptacle cavity.
Flex Disk (a.k.a. shaft plate and "guibo")
The flex disk is the hexagonal rubber item between the transmission and the propeller shaft. Because it must be removed to lower the transmission, I decided to replace it even though it did not appear seriously degraded. Mercedes part number 180-411-06-15; list price $99.00. These are the same on all pontons since mid-1956. [3] They are available through aftermarket suppliers for much cheaper than the Mercedes price. I paid $53.00 for one manufactured by Jurid, the manufacturer of the ones sold by Mercedes. [4]
If not damaged, the six bolts and nine washers can be reused. Originally they were locked by castle nuts and cotter pins although sometime nylok stop nuts are present as previous replacements. The castle nuts are available from Mercedes: list $6.75, part number 183-990-00-55. Places that supply metric nuts and bolts can order them. Size M12, 1.5 pitch.
Before removing these bolts, washers, and nuts, note carefully how they are fitted. Make a diagram. Look carefully at the 190 service manual figures 41- 1/5 and 41-4/1. Note that the three slightly longer bolts (with a knurl on the head) connect the flange on the transmission side with the flex disk. The nuts face the transmission.
The three slightly shorter bolts (conventional hex head) have two washers each. These washers abut both sides of the flex disk. See items 11 in figures 41-1/5 and 41-4/3. Again, the nuts face the transmission.
Finally, be sure to note the correct orientation of the flex disk as shown in the 190 service manual at figure 41-1/4a. The side with the lips/eyebrows over the holes faces the transmission, and those holes fasten to the transmission flange. The long bolts go through the flex disk holes with the lips and fasten the flange on the transmission side.
Release Bearing and Bearing Carrier
This topic was more troublesome to sort out than I expected, but it led to interesting discoveries. For this reason I have laid out what I have learned in considerable detail so the information can be preserved. Some aspects may seem historical and anachronistic, but there is significant potential for confusion when looking for the correct bearing. I have divided this section into discussions of the release bearing itself and the sleeve on which the bearing is carried. Refer to the following photos[5] when reading this section:
Apparently Mercedes has never supplied the sleeve as a separate item with a unique part number. If someone needed a new sleeve from Mercedes, the only option was, and is, to buy the sleeve in combination with the bearing. The original part number for this combo was 121-250-01-15. It included the "old type" sleeve and the "old type" release bearing. That combo is no longer available from Mercedes. What that means is that Mercedes no longer supplies the "old type" sleeve. As discussed below, if an "old type" sleeve is present and in reusable condition, the release bearing appropriate to it is available from Mercedes and, quite limited, in the SKF and FAG bearing vendor aftermarket.
If the sleeve is undamaged, it can be reused. Some people, however, prefer to replace the bearing and sleeve with new ones, to be on the safe side. The "new" bearing-and-sleeve combo Mercedes currently supplies is part number 110-250-00- 15; list price $170.00. This part number supersedes the original 121-250-01-15 number for the "old" combo that is no longer supplied.
At some point after the ponton era Mercedes changed to supplying only the "new type" sleeve. That sleeve requires the "new type" release bearing. If a new sleeve is required, the "new type" is what you will get from Mercedes, but only as part of the "new" combo.
The inside of the sleeve has a small depression. Dab some grease there to keep the sleeve from binding when sliding over the shaft during operation. At the same time lightly grease the splines on the input shaft of the transmission.
(B) Release Bearing (a.k.a. throwout bearing and clutch withdrawal bearing)
Once the transmission is out, the release-bearing-and-sleeve combo is easily removed. Note carefully which side of the old bearing faces the ears of the sleeve. The bearings can be positioned on the sleeve either way, but only one way is correct. The bearing I removed and its new replacement had serrations around the outside edge of the bearing on the side facing away from the sleeve ears. Also the serrated side is the more beveled outer perimeter of the bearing.
I elected to reuse the sleeve as it was undamaged. To remove the old bearing I used a Dremel-type tool with a cutoff wheel. With care, patience, and a steady hand this works fine. Alert: Wear eye protection!
The new release bearing is a press fit onto the sleeve. I put the sleeve in the freezer and heated the new bearing in an electric skillet to maybe 300 degrees (F). When I was ready to assemble the two, I squirted some WD-40 on the sleeve and verified, yet again, the correct orientation of the bearing. Then it slipped right on.
(B.1) New Bearing - M-B part 000-981-43-25
Mercedes lists $85.00 for the "new type" bearing alone; part number 000-981-43- 25. Note this is a sealed ball bearing. The one I bought in a Mercedes box was made by SKF and carried the SKF number 360540. This is not an industry standard bearing, so it is not available generically. Its published dimensions (in millimeters) are:
40.0 inside diameter
69.6 outside diameter
20.5 width
SKF still lists this number as valid. Apparently SKF produces it in batches on demand. Existing stock can be found outside of Mercedes channels. When I was looking for this SKF bearing before I did the work, I received quotes ranging from $65.00 to $135.00 plus shipping. Researching this article, however, has led me to a private American source of these bearings for nearly $50.00 plus shipping. Would that I had done my homework better!
As to equivalents, FAG 526814 B was a direct equivalent to SKF360540. The dimensions are identical, and it appears on the SKF cross-reference list. Apparently this FAG number remains good but only as original equipment, according to FAG. I may have found a private source for this bearing at nearly $50.00. FAG technical data lists this bearing as equivalent to Mercedes bearings as follows: [7]
981-143-25-?? [8]
001-981-52-25 [9]
504-620-90-04 [10]
110-250-00-15 [11]
(B.2) Old Bearing - M-B part 121-254-00-10
Mercedes still supplies the "old type" release bearing: part number 121-254-00-10; list $147.00. I cannot testify as to its SKF number as I have not personally seen this bearing. I suspect it is the SKF 306654 B that Hkan found (see following), but I am not certain.
One member of the International Ponton Owners Group (IPOG), Hkan Johansson, reports that he removed a release bearing from his 219 with SKF number 306654 B on it. SKF reports that this bearing is obsolete and discontinued. The dimensions (in millimeters) of SKF 306654 B are:
40.0 inside diameter
69.0 outside diameter
21.0 width
I may have unearthed some of these bearings from a private source also. The price may be nearly $50.00 plus shipping.
I came across reference to another discontinued FAG bearing, FAG 501929 C. Its dimensions (in millimeters) are:
40.0 inside diameter
69.2 outside diameter
21.5 width
FAG technical data cross reference this bearing to SKF 306654 B. I found a small stock of this FAG 501929 C bearing in the USA from a private source and from Werner Karasch in Germany but nowhere else. [12]
One more relevant FAG bearing came to light: FAG 505310 C. It was identified as being for the "early type" ponton release bearing. I was unable to obtain any dimensions as it is totally obsolete. I cannot compare and contrast it with the other FAG bearing, FAG 501929 C, indicated above as being suitable as the "early type" release bearing.
(B.3) Other Manufacturers
I came across no indication of manufacturers other than SKF or FAG ever making the release bearing for pontons. This research effort led me to speculate that SKF and FAG made the above release bearings only for selected Mercedes and Fiat applications.
(C) Conclusion
The mention by o amigo Alexander, a member of the International Ponton Owners Group (IPOG), of an "early" and "late" release bearing is now clarified. Clearly the "early" type was SKF 306654 B and FAG equivalent, and the "late" type was SKF 306650 and FAG equivalent. Different sleeves were used "early" vis--vis is "late." They must not be interchanged. What this means is that if you locate a new "early-type" bearing, SKF 306654 B or FAG equivalent, you must reuse your "early type" sleeve or find another identical sleeve. Otherwise you must obtain a "late type" sleeve and an SKF 360540 or equivalent FAG bearing. Early-type sleeves cannot be mixed with late-type sleeves and vice versa. I do not know when "early" changed to "late" with respect to any of the ponton models, but I have come to believe it happened after the end of the ponton era. [13]
Confused? I certainly was until I came to realize that the sleeve was never supplied separately and never had its own part number. Now consider yourself informed about that as well as the different bearings.
Driven Disk
The 200-mm clutch disk is now Mercedes part number 010-250-12-03 for all pontons that use the dished-type flywheel. Mercedes list price is $252.00. It is made by Sachs and carries the Sachs number 1861-123-236. It is available much less expensively from aftermarket vendors. I paid $85.00.
The only thing to emphasize here is the correct orientation when installing it. One side is marked getreibe seite. Be sure to position that side towards the pressure plate and the transmission.
Pressure Plate (a.k.a. clutch plate)
The pressure plate for all pontons with the dished-type flywheel is now Mercedes part number180-250-07-04. List price $242.00. This too is made by Sachs, Sachs number 1882-102-132. Widely available in the aftermarket, I paid $106.00.
Sometimes removing the old pressure plate can pose problems. Other times it backs out easily after loosening the screws slowly and gradually, using a cross pattern. In my case it was quite stuck in place. I tapped all around the outside and pulled on it. I squirted penetrant around the beveled edge (I found the seam after removing all the dust and dirt). Still no give. Finally, I used a crow-foot pry bar in the hole where the disk is visible and slowly jiggled it off. All the while I had concern that I might damage the flywheel somehow. No problems.
When installing the pressure plate, be sure to tighten the six screws evenly, using a cross pattern of tightening. I chose to turn each screw one turn, one after the other. You may have to press the plate in with your hand to get the screws started. Tighten to the prescribed torque value. (See separate discussion below of screws and torque values.)
When tightening the pressure plate, the "fingers" will raise slightly from the plate. Pieces looking like large staples should fall out from between the plate and the fingers if you have not previously found and removed them. If they do not, do so now. These are for shipping the pressure plate, not for the system's operation.
The service manual specifies that, depending on the model, there should be a specific distance between the end of the finger and the pressure plate. The specified differences among ponton models is very small. See the 190 service manual at section 25-1/3 and the 180-220S/SE service manual at section 25-1. To adjust this distance one turns the nuts on the bottom of the "fingers." I could not figure out how to obtain a precise measurement while the flywheel was still in the car. Access was too awkward. This procedure, if necessary, is doubtless doable with the engine and flywheel removed from the car. Based on advice I received, I decided to leave the nuts untouched and let any small deviation from specification be handled via the clutch adjustment later.
Flywheel
To do or not to do, that is the question. As a matter of routine, should one remove the flywheel to have it resurfaced? Of course, if its face is obviously scored, this will be necessary as long as "turning" does take it beyond specifications set forth in the service manual. If there is no obvious scoring or other damage, or if the blemishes are very minor, the question of prophylactic resurfacing arises. After all, at this point you have easy access to it. People come down energetically on both sides of the question.
First of all, the flywheel inside and outside is very likely to be dirty and crudded. It needs to be thoroughly cleaned before you can make a determination about resurfacing. I squirted a lot of brake cleaner spray and cleaned off as much crud as would come. Most did. Dried it with paper towels. Then I used WD-40 and 0000-guage steel wool to remove any traces of minor rust and dirt on the face. Then it got carburetor spray treatment and towel cleanup again. Finally, I cleaned off the face and inside side of the cup with PVC plastic pipe cleaner, a liquid cleaner that dries immediately. (This is what is used to clean PVC pipes for gluing.) That flywheel ended up spotless!
Then I examined the flywheel for cracks, other signs of metal fatigue, and grooves. I gave it the thumbnail-scrape test. It was very smooth.
I concluded that the flywheel's condition did not compel resurfacing. Should I resurface it anyway simply because it is now accessible? There was no escaping the question. I finally came down on the side of those who say "if it is not broken, don't fix it." Resurfacing necessarily shortens the life of the flywheel and may weaken it slightly because the process removes metal. Many professionals report they do not routinely resurface flywheels and in fact seldom do so unless the need is obvious.
In the end my reasoning was that every task includes the possibility of error, damage or injury, no matter how careful one may be. Removing the flywheel carries a certain, albeit minor, risk. Giving it to a machinist for resurfacing involves the possibility of loss, mistake, or damage. I could mess up the reinstallation (been there, done that). I could injure myself. In light of the excellent appearance of the flywheel, I weighed the risks involved in resurfacing it. The scales tipped towards leaving things alone. Of course, all this is a personal judgment.
Here I offer an observation. On some cars (not pontons) removing the flywheel provides convenient access to the rear crankshaft seal. Some people want to replace this as a precaution. Sometimes the seal is leaking, so one wants to have access to it. Stand down! Apparently that seal on pontons cannot be reached for replacement simply by removing the flywheel. Generally the engine must be removed and partially disassembled to replace that seal. So if that seal is leaking, the flywheel is not a facile route to it.
Transmission Removal and Reinstallation
Here, I speak only to removing the transmission from beneath the car while the car is on jack stands; that is, for us home garage duffers. My hydraulic floor jack would not lift the car from the front high enough to provide sufficient clearance either to work at the transmission or to drag it out from under the car once it was on the floor. I had to raise the front of the car higher than the jack would go. What to do?
For starters, I activated the emergency brake and put chocks behind the rear wheels to keep the car from rolling backwards. Anticipate safety needs first and always!
Then I placed the hydraulic jack, with a short 2 x 4 wood piece on the lifting plate, under one side's rockers, just forward of the front jack points where the rocker turns towards the engine. Then I raised the jack about two-thirds of its extension. Next I placed a jack stand, also using a similar piece of wood as buffer, under the rocker at about the jack point and extended it. Then I repeated the process on the other side except that I raised the jack to full extension, which resulted in raising the jack stand to near its maximum height. I returned to the first side and raised the jack stand to nearly full extension, using the same jacking process. The reason I lifted the car in stages is that I did not want to twist the body too much. I do not know if this is could be a problem, but I would not risk anything.
This jacking procedure provided ample clearance. The transmission was moved readily from under the car and back. I had plenty of room for access.
Does one need a special transmission jack or transmission adapter for a floor jack? Doubtless it is easier to raise and lower the transmission with such a device than with a regular hydraulic floor jack or with two retirees on their backs struggling with it manually. (I weighed the transmission and bell housing; it weighs 70 pounds/32 kilos.) I used my floor jack and kept a careful hand on it, maneuvering the transmission around. A cloth on the lift plate of the jack reduced slipping around by the transmission. A helper worked the jack handle in response to my commands when I was under the car. Admittedly the transmission came out this way easier than it went back in, but in the end the procedure worked satisfactorily. In sum, using a hydraulic floor jack without any special transmission lifting device is certainly a viable option.
Once the transmission was out, I cleaned its exterior. Inside and outside the bell housing was also cleaned. Everything was very dirty and greasy.
Examine the transmission for leaks. Finding none on mine, I did nothing further to it. I did not disturb the shift levers, one on the top and one on the side. Mechanically the transmission operated properly before I removed it. Know that if you turn the transmission over far enough, fluid will leak out the vent on the top. This vent is beneath a bell-shaped brass cover. I removed the vent and cleaned the screen.
Be careful examining the transmission. You do not want to bend the shift rods or levers. Also, note carefully which rod goes where; they are shaped differently.
Lever the shift fork off the pivot ball. Do not lose the locking ring in the socket. Clean and grease everything. Reinstall.
Replacement items
I decided to replace every rubber bit associated with the entire enterprise plus a few other things. That included the two round rubber bushings [14] where the shift levers fit to the shift rods on the transmission.
For this discussion note the following illustrations from the Type 220S spare parts book [15], Catalogue "C," dated 1958. Illustrated spare parts books for other pontons will have comparable pages.
Table 17. "Pedals"
Connecting to the clutch-adjusting bracket (item 62) is a rod (item 37) with a rubber bushing, item 61. Drive this out and drive in a replacement. In doing so, note that one end is beveled, so drive it from the other end. Mercedes part number 186-988-00-10; list price $13.00. Cover cap 120-291-02-88, list $5.00, needs to be replaced; item 49. So too with rubber bushing, item 48, part number 120-291-03-88; list price $9.25.The brake control rod fits into a bracket (item 25), specifically into something resembling a thick wedding ring, item 46 (do not lose this ring: 186-991-00-29, list $33.50). Inside that ring is a needle cage, item 45. I replaced it, part number 000-98-18-10, as it was destroyed; list price $19.50. The "wedding ring" is stabilized inside item 25 by a small spring plate (sometimes shown in parts depictions as item 47a and other times not shown but required nevertheless); 121-993-00-26, list $19.50. Be sure you have the correct washer, item 44; Mercedes 000-988-010-016, list $1.00. This washer is DIN standard 10 x 16 x 1.
Look at the rubber pieces that fit between the brake and clutch pedal rods (item 55) and the firewall on the engine side. They are probably mush or even nonexistent by now. I replaced mine on each pedal; they are identical. Mercedes number 120-291-03-97, list $4.00. I also replaced the washers, item 54. Part number 136-224-01-66; list price $2.00. This replacement allowed me to be certain I would obtain the correct clutch adjustment as it keys off the brake pedal as prescribed in the service manual.
Note item 57 (Mercedes number 136-290-00-67) where the pedals are depicted. It is misleading. This is a leather piece riveted to a metal piece. It fits inside a plate around the pedal rods on the driver side of the firewall. At $49.00 list price each, I chose not to replace them.
Table 12. "Clutch"
The rubber fork cover is Mercedes part number 120-254-00-97; list price $3.20. By now yours will be torn and stiff. You may have to fabricate the gaskets on item 42, cover plate. I did.
Note a threaded hole about two-thirds of the way towards the top on the left side of the bell housing. It takes a washer and an air bleed screw, items 34 and 35. This screw is some kind of venting device because it has a tube extending from the bottom of the shaft to inside the head where it branches to the opposite head flats. Don't simply plug the hole with a regular screw. A new bleeding screw, part number120-251-00-71, lists at $29.50. Frankly, I did not understand why this air bleed is necessary as air seemingly enters the bell housing from other places.
Not shown on any of the above illustrations is the rubber bushing that fits between the transmission and drive shaft flanges. It is part number 120-411-00-60; list $2.20. I replaced it.
Reverse Light Switch
Table 16. "Transmission"
The wire harness (not depicted above) to the reverse lights switch on the transmission, item 7a, connects to it by two tiny screws. Don't misplace them. If the switch worked OK, leave it alone except to clean it and remove corrosion around the screw holes. I do not know if it is necessary, but I took careful note of which color wire attached to which terminal on both ends.Probably the wire harness will be cracked and oil-soaked. I fabricated a new one. See for the general approach:
http://www.mbzponton.org/valueadded/technical/harness.htm
The original harness was 26 inches/66 centimeters long. I recall using12-gage stranded wire.
The rubber boot (number 98 in the illustration) covering the brass switch where the reverse light wires connect is part number 000-546-00-35; list price $5.00. And no, it is not identical to the boots on the generator and coil.
Note that there should be a rubber boot covering where the positive battery cable connects to the starter solenoid. This boot is identical to the one that fits over the reverse light switch on the transmission.
Torque Requirements
My flywheel was fastened by screws that had the marking 12.9 on them. That meant they were highly hardened in metric terms. As I did not remove the flywheel, I did not disturb them.
Considerable discussion developed as to the correct torque value for the flywheel screws, and it became almost esoteric. Opinions varied as to the correct torque. Then, as he was proof reading the final article, Jeff Miller referenced the "Mercedes-Benz Technical Data Passenger Cars" (December 1957 Edition, page 123) and found the flywheel tightening torques to be listed as follows: 6-6.5 mkg [16] for the Types 180a, 190 and 190SL. The Types 219, 220a and 220S have a tightening torque of 4.5-5 mkg.
I found myself concerned with the six screws that fixed the pressure plate to the flywheel, item 19 in Table 12 above. The screws I removed were marked "8G." This was the hardening indicator. It is not the current metric hardening numbering system, so I was confused about how much torque to apply when reinstalling the screws. Again much discussion ensued, which I initiated. Hkan Johanssen and Jim Davis were instrumental in clearing up confusion. The conclusion is that the"8G" screw I removed meant today's 8.8 metric hardening. See:
- http://frugalmachinist.com/Metric.htm
Before this got resolved, I decided to get new screws. The new screws, Mercedes number 304-017-008-048 (list price $1.40), came with a hardening mark of 10.9. This suggests Mercedes increased the torque value for this application. Search as I did, nowhere did I find any authoritative Mercedes document specifying the correct torque for these screws. Web sites indicating the torque for untreated M8 screws with a 10.9 hardening value ranged between about 25 lb. ft. and 36 lb.ft. See the following sites and take your pick:
- http://karmannghia.org/bitmaps/metric.gif
- http://euler9.tripod.com/bolt-database/22.html
- http://www.fastenal.com/resources/online_calculators/metric_torque/metricTorque.asp
- http://www.190slgroup.com/tech/pic_part/Metric_torques.pdf
- http://www.mdmetric.com/tech/tech4/3.htm
I put a touch of antiseize lubricant on the bottom threads of each screw and went to 35 lb. ft. torque. Nothing snapped.
The pressure plate screws presented another, more or less academic, curiosity. The Mercedes parts manual lists M8x28 DIN 931 and then M8x20 DIN 933 as replacement. The former is slightly longer and has threads part way up the shank. The latter is slightly shorter and has screw threads all the way to the head. Was this significant? Did this change mean that something else had changed along with this different screw? Something expensive? Perhaps nothing more than a bulk-purchasing convenience? I don't know, but I don't think so. The difference in length is eight millimeters. The screws I removed and the ones I bought were of the subsequent M8x20 DIN 933 designation although, as noted above, the hardening mark differed.
Disclaimer: The author has provided accurate information based on his research and personal experience. Use the information at your own risk. Verify it to your own satisfaction. No guaranteed is implied or warranted.
Request: Suggestions for additions and corrections are welcome.
Thanks: Particular thanks go to Jeff Miller, the curator-editor of the Mercedes-Benz Ponton web site. As usual, he labored mightily to transform this document into a usable web page. Len Sokoloff provided the scans from the Type 220S picture parts book. o amigo Alexander, Jim Davis, and Henry Magno provided prepublication peer review which was indispensable. They are not responsible for any errors.
Footnotes
[1] a.k.a. = also known as.
[1a] "Industry standard" refers to bearings that have specified characteristics and tolerances that meet established industry norms. Any bearing manufacturer would have to meet those norms. Therefore, any bearing marked with the 6202 number, whether made by SKF, FAG, or other, would meet those norms for the 6202 and would be interchangeable one with another. Mercedes and other auto makers use such bearings, often in several applications within the same vehicle and on different models. The same happens with oil and grease seals. On rare occasions, however, seals and bearings are unique to a specific vehicle application. They are still available in the bearing market, but sometimes not at such a great cost percentage savings as with industry standard items.
[2] Interesting to note that the 6202 standard bearing fits the following additional applications on pontons: (1) 180b and 180D (1956-58) - fan front and rear, water pump, injection pump drive (180D only); (2) 180a, 190, 190D, 190SL, 220a, 220S (1956-59) - water pump; (3) 180b, 180DC, 180c, 180Dc water pump rear, fan pulley front and rear, injection pump drive. Apparently the 220SE did not use the 6202 bearing anywhere, or the literature simply failed to mention the 220SE, or the 220SE was discussed on a page I did not receive.
[3] For details see section 41-4/1 of the 180220S/SE service manual.
[4] Thierry Savidan reports he bought a new one in Thailand for US$10.00.
[5] Courtesy of o amigo Alexander.
[6] Sometimes called the release bearing carrier. Confusion may arise when dealing with German suppliers and German translations. Sometimes the German, when discussion this item in English, refers to it as "release bearing" because it "bears" the ball bearing (which in English we call "release bearing"). Until I realized what was happening, this caused me not a small amount of confusion when communicating with native German speakers. For native English speakers the "release bearing" is the special sealed ball bearing. For the German "release bearing" can refer to what we call the sleeve or carrier.
[7] FAG technical data also list this bearing as equivalent to SKF 616524 and SKF 616524 A which SKF reports to be obsolete and discontinued. These bearings had the following dimensions (in mm): 40.0 inside diameter, 70.0 outside diameter, 18.0 width. This is extremely close to the dimensions of SKF 306540 and the discontinued SKF 306654 B.
[8] This number is obviously screwy. It does carry the 981 number which is Mercedes-Benz speak for bearings.
[9] Mercedes-Benz reports that this number has been supersedes by 000-981-43-02. This is their current bearing number for the pontons and is SKF 360540. Note the 981 bearing series number.
[10] No longer a valid number.
[11] Note, this is the same number M-B currently uses for the "new type" combo.
[12] Karasch offers FAG 501929 C for 74.00 plus shipping.
[13] Just to confuse matters, courtesy of Hken Johansson I have a copy of an SKF product sheet for the ponton range. It lists SKF 306564 B as the clutch release bearing for all ponton models, except the 220SE, for the duration of their production. Thus I cannot say for certain when the SKF 306540, with its slightly different dimensions and with its requirement for a different sleeve, came into use. But come into use it did, and M-B now supplies it for the ponton clutch release bearing application.
[14] My 180-series transmission wore a Type W111 "Fintail" series cover. This combination works fine. I assume this happened when my car was converted from Hydrak during the 1960s. The rubber bushings are different, so I am not providing the part number.
[15] Courtesy of Len Sokoloff.
[16] 1 mkg (kilogram-meter) = 7.233 ft-lbs.
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