I wanted to show you guys why my "Clutch failed." I ended up having to drive my 240D without a functional clutch from Black Mountain, NC to Travelers Rest, SC. (about 50miles) I thought the slave had failed but I was wrong. Tuns out that the push rod from the slave wore its way through the clutch fork. 304k of metal on metal wear.




I swear.... I'm going to have this transmission back together tonight.

Obviously someone shifted too much!

Just kidding. These things last a long time but not forever. Some stuff does wear out.

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[SIGPIC] Diesel loving autocrossing grandpa Architect. 08 Dodge 3/4 ton with Cummins & six speed; I have had about 35 benzes. I have a 39 Studebaker Coupe Express pickup in which I have had installed a 617 turbo and a five speed manual.[SIGPIC]

..I also have a 427 Cobra replica with an aluminum chassis.

Interesting failure! I'll have my trans out in a few weeks (I need to come up with a stronger clutch now that the engine is making significantly more HP - I'll post up once I have something that works) so I'll be sure to check that throw-out arm. I'm pretty sure I lubed that spot when I installed the trans and I'd like to think I'd have noticed but I AM old!

Thanks for posting this.

Dan

Aaaaand.... The transmission is NOT back together .

I believe I'm going to need to add some shims to the bearing on the intermediate plate. I've assembled it on the bench and when I tighten the bolts for the rear cover the trans doesn't spin freely in neutral. If i loosen the bolts just a little, I can see the case separate slightly and then everything works smooth as butter.

Here's a pic of the bearing I think I need to add shims to. It had two shims to begin with.



How concerned should I be with adding shims to push it out about an additional 1.0mm. The existing shims had a total thickness of .6mm. Perhaps adding all new bearings changed this somewhat, but that doesn't make sense to me unless one of the new main bearings had a variance of 1.0mm compared to the old and I'm not about to pull the whole thing back apart just to put a caliper on the input shaft bearing to find out.... I'm hoping to draw from the experience of someone else here, but for now I'm on the hunt for some shims....

New parts I installed were bearings (all of them) and new synchro rings.

So funny to see pictures of parts I used to have in someone else's hands . Hope it works out for you!

What all are you replacing in the transmission? Where are you getting the parts from? Sounds interesting...

EDIT: And, if you don't mind me asking, how much is it?

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"Senior Luna, your sense of humor is still loco... but we love it, anyway." -rickymay ____ "Your sense of humor is still loco... " -MBeige ____ "Señor Luna, your sense of humor is quite järjetön" -Delibes

1982 300SD -- 211k, Texas car, tranny issues ____ 1979 240D 4-speed 234k -- turbo and tuned IP, third world taxi hot rod

2 Samuel 12:13: "David said to Nathan, “I have sinned against the Lord.” And Nathan said to David, “The Lord also has put away your sin; you shall not die."

I've replaced the input shaft bearing, output shaft bearing, both bearings on the lay shaft, and all the roller bearings on the output shaft. I've replaced the brass synchro rings along with the clips that hold them and all the seals and gaskets on the entire transmission.

All the parts I've used are genuine Mercedes. Looking back it would have been cheaper and much easier to just slap the trans back in the car as is and source a used one if anything ever happened. I've probably spent about $500 or so in parts for just the transmission. Bearings are expensive I found them from $49-$77 each (list was $115 for a couple of them!) and the synchro rings were around $70 each. Master gasket kit is about $50, oil is about $40. It adds up quick. If you're thinking about doing one you'd need to take into account the tools you'll need. Quality snap ring pliers, dead blow hammer, brass drift set access to a press. Not sure if its worth it. I could put the whole thing back together for it to blow up in 5k miles...

Looking back I'd probably not rebuild it. I haven't had a transmission apart and back together since I was in an auto tech class about 13 years ago. It's definitely rewarding when the whole thing goes back nicely and shifts, but frustrating and expensive when it doesn't.

After going to 3 machine shops with no success I decided to modify the pilot bearing OD on my own.

I used a 13mm hex driver mounted on an extension for a handle and pressed it against the grinding wheel. I used my thumb as a break to slow the spinning of the bearing. Watching the sparks I could tell whether or not I was grinding flat or at an angle.


It took a long time as I kept stopping as soon as the bearing warmed up. But I think I've got what I'm looking for.

That's about how I did mine. Not ideal but functional. And mine works OK.

Dan

A couple steps closer....

The flywheel has been resurfaced, now I just need to find a shop that can match balance it to the auto.



And the transmission is back together!

It's been a while since I've posted because there's been no work completed on the Benz until yesterday. I've been driving all around North and South Carolina trying to find a machine shop to match balance these two flywheels. I've gone to about 8 different shops. Half the shops I visit don't have a balance machine and the other half can't/won't perform the work. Most want me to disassemble the entire engine and bring them all internals. I couldn't even talk anyone into putting each flywheel on the machine and telling me what the out of balance was.

Not wanting to ship 50lbs of metal across the country twice, or buy a balance machine, I decided to statically balance it the best I could. Long story short, I ended up drilling out about 10g of material from the 300D flywheel and slapping it in there yesterday afternoon.

I need to run to the store for a 3ft extension so I can reach the bolts on the starter and top of the bell housing, but I'm hoping to start this thing up at some point today and see how bad it shakes

I called a custom engine shop, and told em what I was doing and needed the flywheel balanced and resurfaced. He asked what car it was for and I told him an old diesel mercedes. His response was "oh yeah I've done a few of those, bring it in". His quote was $80-150

According to the FSM it only takes a mandrel to match balance the flywheels to each other..

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1980 240d ,

chain elongation, cam marks reference:
http://www.peachparts.com/shopforum/diesel-discussion/10414-help-i-need-check-stretch.html

http://www.peachparts.com/shopforum/diesel-discussion/305365-9-degrees-chain-stretch.html

evap fin cleaning:

http://www.peachparts.com/shopforum/diesel-discussion/156207-photo-step-step-post-showing-w123-evaporator-removal-1983-240d-1982-300td.html?highlight=evaporator

A/C thread

http://www.peachparts.com/shopforum/diesel-discussion/297462-c-recommendations-mb-vehicles.html

A mandrel match balance is basically what I ended up doing. Apparently it's close enough

https://youtu.be/LMezI1z86-Y

Modified my shift linkages and installed them this past Friday. This is the first time I've been able to shift the car since rebuilding the shifter. What a huge difference the rebuild made! No longer need to guess where the gears are.






I'm getting better at welding. Please excuse the Hemi orange paint. I went for the black, but the can wouldn't spray. Heck, its underneath the car anyway.

The driveshaft shop should have my front shaft complete sometime next week. If that's true and the retainer nuts I need for the trans mount arrive I'll be taking it for a drive next weekend.

One slight concern I have is the positive battery cable routing. I'm thinking the 300D must have been different. I think the turbo downpipe is too close to the battery cable. The battery cable has the factory rubber shield, and I've wrapped it in 2000 degree heat resistant metal/fiberglass shielding.

I wish I had space to have kept the 300D around until the swap was completed...