shotgun_banjo

I have this "thunk" noise on my transmission when I shift from park to drive and drive to park just after starting the car. It literally sounds like a manual transmission car that you shift and the gear gets caught or something. Also I noticed that I have a harsher shift shock on the 2nd to 3rd and 3rd to 2nd gear in the first 5 minutes driving the car from cold. The weird thing is the thunk noise goes away after the car heats up but the harsh shifting occasionally happens.

Is this a symptom of tranny problem? Should I take it to the dealer to get it looked at or is it plain normal for a aging c-class?

Glyn M Ruck

Check rear transmission mount, flex discs, centre prop bearing etc. for damage.

Mr.Mango

This is normal operation. However it never hurts to check for leaks and change out the transmission fluid.

It uses harsher shift engagement / higher line pressure, & locks up the torque converter later in order to acheive operating temp quicker. Line pressure is low in park, when you shift into drive or reverse it drastically increases swiftly engaging the correct clutches. Thats the drivetrain "shock" your feeling.

victort

I had the same problem since my car was new back in 2010. Dealers weren't able to fix it throughout the years. Decided to just get rid of it since my warranty is about to expire and got a Lexus instead.