Crazy vibration...
 

This is on my 01 TA a4. When the it's in drive or even reverse, say at a red light, it feels like it's going to vibrate apart. If I put it in neutral the vibration goes away. I just replaced the trans mount, seems like it got worse. Any ideas?

Re: Crazy vibration...
 

Check your motor mounts and everything that the motor and trans attaches to. Then just keep checking down the drive line until you find something wrong. You can also put it up on jack stands and run the car with it in drive while you watch underneath, but I don't recommend that.

Re: Crazy vibration...
 

Found it! The passenger side cat was sitting against the the subframe. I found the quickest way to get some seperation was to put two 18 ga shims between the trans mount and the cross member. Obviously there is an under lying cause such as a worn motor mount but I'm not seeing the common signs of that. Probably fab up a stainless pipe to replace the cat.