thunk in reverse

[rdmac]

Any body notice that when you put your car in reverse there is a slight thunk sometimes. Not a big deal we have 7 years on the drive train. Dealer tells my its typical on the rear wheel drive.

Bob

[LakersFan]

Yeah, that happens to mine as well. Its annoying! Im glad its not just mine though, but im sorry to hear it happens to you too!

[rdmac]

Well good news / bad news. It is a little annoying but I'm glad it appears to not be just me and is somewhat normal.

Bob

[GMLind]

Is it possible the parking brake is stuck, or disengaging from the rear wheels. Some vehicles (Escalade) will have a thunk sometimes when going from start to first or reverse. The thunk is due to the tranny program telling it to stay in neutral or park longer than you expect, and then finally, engaging after a bit of throttle. A bit annoying but not really anything to worry about.

[mileshoover]

FWIW --

Anyone notice the warning in the Owner's Manual about setting Park on the tranny BEFORE setting the parking brake?

This is a bit unusual for me since I always use the Park rather than the parking brake. My driveway also has a slight incline to the garage. IF I set the park on that incline, the car apparently drifts back against the parking pawl and can LOCK it into place. The manual states HOW you can release it if that happens and you can't pull it out. Briefly, you must remove the disk holder bin along side the tranny lever, reach in and pop the tranny out of park.

I also notice when I put the tranny into park on the incline, that the tranny would "thunk" when shifting to reverse. So, it appears that one should NOT use the park position as a "park" arrangement unless first applying the parking brake. Apparently, the Germans currently have a different view for the use of "Park" which I never had happen on my 2 earlier Benz's.

The other way is an old, old habit with me and will take a lot of retraining of this old dog. But for me as of now, no more using the park position only for holding the car on an incline, for sure.
Don't want to induce any tranny troubles.

[Tornnight]

This is something I have been practicing forever. I have been a honda owner (Civic then Accord) and they both 'Lock' and thunk if you don't put the parking brake up before putting it in park while on an incline. I always thought that the reason is that all the weight of the car is now on the transmission and it's basically having a hard time disengaging itself with that pressure.

Dunno what your Benzes do differently where this doesn't occur.

[mileshoover]

Originally Posted by Tornnight

This is something I have been practicing forever. I have been a honda owner (Civic then Accord) and they both 'Lock' and thunk if you don't put the parking brake up before putting it in park while on an incline. I always thought that the reason is that all the weight of the car is now on the transmission and it's basically having a hard time disengaging itself with that pressure.

Dunno what your Benzes do differently where this doesn't occur.

I'm sure that you are correct. It didn't seem to bother the Benz's but they were an '85 and '88; both had GM trannys on them at that time.

I guess that American cars were a bit more forgiving but, yes, I can recall some of that same kind of "thunk" with other earlier cars, too. My wife's Acura Integra LS likewise will give you a fit if you leave it in park only on a incline. Guess I must learn better driving habits.

[Sting2114]

Hey guys, don't worry about that problem. I have had that problem on my auto and so have my friends on a variety of GM cars. The exact same problem you are describing. Little lesson the transmission, as long as you pay attention to the transmission fluid and aren't a penny pincher when it comes to getting changed (gonna write this in caps) BY A PROFESSIONAL (you do not count as a pro) with a PROFESSIONAL transmission fluid flush/changer, you'll be fine. But don't be a loser and be like, "oh it's not supposed to be changed till xyz miles even though it looks like it's the wrong color", because I know people who have done that...Guess what happened to'em? They ended up having to get a new trainey every time.