Frequently, after coasting, when I press the gas pedal, I will immediately hear and feel a light "Clunk" in the drive train - It reminds me of what happens when a stopped train starts up and you hear a clunk each time a car takes up the slack with the car behind it.

Any idea what would cause this?

 

Hi ArkMan,

I am sorry to hear you're experiencing this clunk in your drivetrain. Have you reached out to your dealership to discuss what may be the cause? If this is something you would like assistance setting up, please PM us your full contact info, VIN, mileage, and dealership name/location.

Sincerely,

Jonathan A.
Cadillac Customer Care

 

you can't even get anybody to participate in your question. I would love to answer your question but it sounds about right, your tranny needs to be serviced. I just bought a DTS and found out the guy replaced the tranny already. GMC does not surprise me at all to have tranny problems. I hope people who knows cars will know how to answer your post.

 

Check the Engine Mounts. I have a 2002, and it would clunk also when the engine bounced on it. I'm not sure where they're located on a 2009. I had to replace 2 of them, and it cost me between $600-$700 at the Cadillac dealer.

TS

 

Thanks for the suggestions. Unless this is an urgent issue, I will wait and have it checked at the next service and then post what was found.

 

I agree with engine mounts, there are a few, I replaced one in a friends 2002 Deville, front mount. Its not a job for an inexperienced person because you have to loosen the engine cradled and drop the engine about 3 inches to gain access. The part was $89 and it took 3 hours. Not for the average back yard mechanic but it is a rather simple job its just that engine lowering part that may be beyond many guys abilities.