I have a 1991 420SEL (722.355 tranny) that is starting to have problems with the tranny. I suspect it is going to need a rebuild. While I have done a lot of DIY jobs on my three MBZ, I have not rebuilt a MBZ tranny before.

I have searched this and other forums with little success for information on a DIY rebuild, but have found information on evaluating the tranny. I know a transmission rebuild requires extreme attention to detail. I have found a manual for the transmission, but would like some information on the best approach from someone who has rebuilt this tranny. I would appreciate pictures and/or suggestions.

 

Several different symptoms:

1. The car shudders when it first starts to move in reverse.

2. I occasionally doesn't want to move when in drive. It acts like a brake caliper is stuck, but it is not.

3. On one occasion, while it was doing #2 above, I stopped and shifted gears (park, reverse, etc.) and it wanted to go into reverse when the shifter indicated neutral.

4. It made a real chattering noise one morning in drive.

5. The tranny slips sometimes after slowing down and then accelerating again.

6. It flares on fast acceleration, but not so much on slow acceleration.

 

Thank you very much, ForcedInduction. Your information is most helpful.

It sounds like you recommend that I do a complete flush with new filter, and replace the modulator before doing a rebuild?