Turc928S4

Was having issues with the transmission and decided to investigate... a bit

Here are the K1 steel plates. It might have slipped a bit based on the hot spots.




Then, I checked the reverse friction disk.




Here's a closer look.




Finally K2 steel, which I think is salvageable. Only one hot spot.

Lizard928

Looks like 90% of the B3 friction plates I've removed.

Turc928S4

Do you know what causes them to be so damaged? Any suggestions on which rebuild kit to go for? I was planning on getting the MB rebuild kit, MB friction disks and band, and oem steel.

Ducman82

looks like your syncros have cancer.

GregBBRD

What year?

Turc928S4

this is a 1987 s4 but it's not the original transmission. The original was a limited slip diff and this one is not.

ammonman

Post pictures of the numbers stamped on the bottom of the diff case rib as well. That will help tell the story of model year, etc.

Mike

GregBBRD

^^^^^^Yes. This is the number needed.^^^^^^

Those Mercedes numbers mean something to someone....but no one has ever found him.

Turc928S4

Sorry, forgot that one. It's a A28/12 1987 (H) with no limited-slip differential.

GregBBRD

What people don't realize is that the internal o-rings and seals in these transmissions were rock hard 15 years ago, allowing pressure leakage and slipping. It is rare to find clutches, these days, that are not ruined from heat.

Unfortunately, the steel clutch pieces have gone up in price several hundreds of percent.....and are now very expensive.

The lining coming off of reverse is common. Mercedes changed the clutch material many years ago, to help with this problem.

There are many updates that should be done to update these '87 4 speeds to make them work better.

If you buy all the seals for the differential (you should), input shaft bearings, brake bands, and do the proper updates, there's about 2K in parts needed.

Be careful of buying "offshore" pieces. While there are SOME quality offshore pieces that do function well, they just dont last as long. In short, if it doesn't come from Mercedes, you need to think long and hard before using it.

And remember, if it doesn't work well, when you are done, I've still got a couple of these transmissions tucked away....brand new Porsche transmiscions, with limited slips.

Turc928S4

Is it possible that the piston brake band 107 270 04 32 has many flavours? I seem to have the latest version which shows 126 277 05 38, but when I see pictures of the new part, is shows 126 277 11 38.