Jam Hamidi / email@example.com / California USA
1959 Mercedes-Benz Type 220S
Just got back from the mandatory Memorial Day barbecue. We drove the Ponton, and it was a blast. Up through the hilly Eldorado roads, everything green and lush because of all the rain we 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" at EMB Co. / Fairfax, Virginia / Note: as of 2016, EMB is no longer in business.
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 an 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.) Note: as of 2016, EMB is no longer in business. She sent 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 smoothly.
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!
May 27, 2002