Drivetrain slop

[westcoast1er]

Hey guys,

I have a 2011 DCT car. with 83k km I notice the on and off throttle applications are not smooth at all. There feels to be significant movement in the driveline (motor, trans) that shudder/jerks the car.

Is this common? Is there a fix or solution (stiffer engine/trans mounts) that does not impinge upon NVH more than it would be solving?

I appreciate all insight!


Thanks.

[Tiron]

My 2009 with 115k miles (would be around 185k km) has this exact same feeling. I have done the whiteline rear subframe inserts, which did help a little, but I think in my case its the differential bushings gone bad. I know my motor mounts are tired too, but I don't think they are loose enough to make the clunk I can hear/feel. There are any number of control arm or rear subframe bushings that could make a clunk like you describe.

The solution is to replace all the worn bushings and mounts, if you use factory parts it should feel like factory when you're done, with no extra NVH. Aftermarket parts that are stiffer will increase NVH (sometimes only a small amount though).

[westcoast1er]

Originally Posted by Tiron

My 2009 with 115k miles (would be around 185k km) has this exact same feeling. I have done the whiteline rear subframe inserts, which did help a little, but I think in my case its the differential bushings gone bad. I know my motor mounts are tired too, but I don't think they are loose enough to make the clunk I can hear/feel. There are any number of control arm or rear subframe bushings that could make a clunk like you describe.

The solution is to replace all the worn bushings and mounts, if you use factory parts it should feel like factory when you're done, with no extra NVH. Aftermarket parts that are stiffer will increase NVH (sometimes only a small amount though).

It feels mainly in the driveline and not so much in the suspension. I will do the rear subframe inserts when I do the m3 front control arm kit. But that is all in due time. Just don't get the extreme play in the motor/trans/diff.

[ignote]

Originally Posted by westcoast1er

Hey guys,

I have a 2011 DCT car. with 83k km I notice the on and off throttle applications are not smooth at all. There feels to be significant movement in the driveline (motor, trans) that shudder/jerks the car.

Is this common? Is there a fix or solution (stiffer engine/trans mounts) that does not impinge upon NVH more than it would be solving?

I appreciate all insight!


Thanks.

You most likely need to get the latest DME software or the PPK flash. The DCT lag is a common problem.
I got the PPK flash and it fixed the issue.

[westcoast1er]

Originally Posted by ignote

You most likely need to get the latest DME software or the PPK flash. The DCT lag is a common problem.
I got the PPK flash and it fixed the issue.

It feels much more mechanical or physical as opposed to software related. Almost like a broken engine/trans mount.

[Tiron]

Do you have a way to get under the car and take a look? I think the motor mounts are hard to see, but the trans mounts and rear diff mounts shouldn't be too bad to inspect. Motor / trans / diff mounts are the first things I'd check. I think they are common wear items (especially the diff mounts).