Transmission

Did you lose a wheel weight?

Thats the first thing I checked. I re balanced the tires with no change.
Someone hinted at motor mounts. But the car was perfect except for the shifting problem. Then this. I guess its back to the shop. Thanks for reply.

Did they remove the transmission? The dogbone pendulum mount (rear lower transmission mount) and all motor mount bolts are single use stretch bolts only. If they get reused they can break. The motor mount is aluminum so if the threads are damaged it can cause the engine to fall down. Make sure the shop uses all new stretch bolts if they loosen the motor mount or dogbone mount.

If not, then it's possible the axles aren't tight or straight.

I don't think there's a problem inside the transmission but it's possible. If you shift into neutral does it change?

They did remove the tranny. I know they didnt use any new hardware as they would of been on the bill. I need to make a call and check that out.
I don't think having the engine come down would make for a good day. Thanks for the good info.

Well you were right on. The rubber pieces in the mounts have colapsed.
I am having new mounts installed as soon as they come in. Thanks for your comments. They saved me alot of work.

* all new bolts too

It's pretty easy to remove it if you can jack up the car.

http://www.myturbodiesel.com/1000q_how_to/a4/dogbonemount.htm

You don't need to take it apart if you are putting in a new one, just unbolt, rebolt.

If the problem is still unresolved, just replace the transmission with a new or rebuild unit. With that, also replace all monts.

It could be a mount but I wouldn't replace the transmission just to fix a vibration especially when only the valve body was replaced.

I'm posting out of frustration. An 05 Passat TDI, automatic. Vibration at idle in gear has been growing over one year in spite of having the Balance shaft upgrade(Oilhammer) with motor mounts replaced, and more recently putting in axle replacements(Raxles) without improvement. It's been cold, so I haven't gone looking for the transmission mounts yet.

Could it be them? It sounds like a rare problem, or no?


Tom
Springfield MO

If you shift into neutral at a stoplight, does it change? If it gets better it's the axles for sure.

If Oilhammer is close to you the best bet is to go see him again. I doubt the motor or transmission mounts are causing the problem. The motorM are new and transM are just rubber pieces and I don't think they are likely to cause idle at vibration. If oilhammer did the balance shaft it's probably not related to the balance shaft.

It gets better when I shift to neutral, but replacing the axles didn't improve it. I did that just two weeks ago. Raxles has a good reputation, and I followed the very good how-to you have posted.

If I get under the car (on jack stands) and watch it while running, and have someone shift to D and hold the brake, what are the odds of seeing something that explains this?

One more thought about this: When the cover is off, you look at the engine running. Your helper shifts to R, then N, then D. To me it looks like the engine moves a lot, nose up for D, nose down for R, more than I have noticed in other(gasser) cars. Does VW have a spec for this amount? It seems that if this amount of movement is large, there is more potetntial for vibration.

This is normal. I don't know the spec for movement but there is a snub mount on the front of the oil pan which connects to a bumper support tube. If this mount is worn it can result in excess movement but I don't think that it's contributing to vibration at idle.

Maybe the Left and Right axles are swapped or the incorrect length causing contact and sending vibration through the steering knuckle? They are different lengths.