I have a 1992 Mercedes 400E with approx. 156K miles. I am the 3rd owner (bought the car with 135K miles) and based on the records that I have, I believe the transmission has not been replaced or rebuilt.

I did drain the transmission, change the filter, and replaced fluid at about 145K miles. I realized later that I did not drain the Torque Converter, so I basically only replaced about 4-5 quarts of fluid out of the system.

Some problems that I notice with the transmission:

* I sometimes (not always) get a loud squealing noise (sounds similar to a drive belt slipping) when the car shifts from 1st to 2nd and when it shifts from 2nd to 3rd. This is most noticeable when the air temperature is high (>85F) and during the first few miles after the car is started cold. I do not notice it much after the car is completely warmed up or when both air temp and car are cold.

* The shift from 1st to 2nd seems to be somewhat slow and not real firm. If you are accelerating rapidly, there is a noticeable drop in the engine RPM during the shift.

* Putting the car into reverse results in a delay of up to 10 seconds or so before reverse engages. If you are on a downhill and shift into reverse, even after waiting for reverse to engage, you need to give it some gas to avoid roll-down.

How about transmission fluid type? When I changed the automatic transmission fluid, I used fluid marked as ATF (Dexron III) based on what I could find in the manual. Is this the appropriate fluid for the Mercedes 1992 400E?

Are the problems that I have described serious in nature? Are there any adjustments or minor repairs that might help the situation?

Thanks for all the help! The forums are really great.

Kim