The transmission mounts don’t often go bad but here is an article since I had remove them in an unrelated job.This article just for share how to replace the transmission mount on a VW Passat TDI. It also applies to the Audi A4.
What tools you need for replace transmission mounts?
2.various extensions and u-joints
Procedure of Transmission mount replacement:
First loosen the front wheel lug bolts. It’s much easier to get access to the bolts with the wheels off.
Raise the car and rest it on jack stands at the factory jack points, making sure the car is safe and securely raised before getting under the car. Chock the rear wheels and double check all safety and jack equipment. Then finish removing the front wheel lug bolts and remove the wheel.
The passenger side mount bolt is covered by a heat shield. The driver’s side mount is the same except there’s no heat shield.
First remove the T-25 torx screw holding the plastic shields on each side around the driveaxles. Ignore the yellow arrow, the pic is from another writeup.
Once it’s off you can see the CV boot heat shield. You’ll probably have to remove it (3x 6mm allen bolts) for access.
Remove the heat shield (3x 10mm bolts) on the passenger side. Here it is removed. You can now see the 16mm bolt holding the transmission mount.
Here is another view with the transmission out of the car. The bolts are indicated by the yellow arrows below. You might be able to bend the heatshield to get access to the bolt but I didn’t want to.
The driver’s side is the same but there’s no heatshield.
Loosen all the 13 and 16mm mount bolts on both sides before removing any of them. This will hold the mount and transmission steady while you loosen the other bolts.
Counterhold the 16mm bolt on top of the mount while loosening the 15mm nut on the bottom. If you don’t counterhold it the bolt will just spin. Remove the 2x 13mm bolts holding the transmission mount to the subframe.
Place a wide, flat piece of wood under the steel transmission fluid pan and use a jack to support it. Don’t put the jack pad directly on the pan because it can dent the pan, changing the fluid level inside the transmission.
Use the jack to slightly lift the rear of the transmission to slip the mounts out. Caution – don’t put your hand between the mount, subframe, or transmission at any time! Don’t place any part of your body in a position where it could be pinched if the transmission moves at all because it could be crushed!
Put the new mounts in place with all the bolts loosely in place. Don’t tighten them yet! If you removed the engine mounts or subframe then it could be out of alignment. If you only replaced the mounts it should be good. There’s some play in the bolt holes and you want to make sure the transmission is straight.
Look at the transmission tunnel, the exhaust, and the driveaxles. Again, if you didn’t touch the motor mounts or subframe it should be good. First tighten the 2x 13mm transmission mount-subframe bolts. Then tighten the 16mm mount bolt. This will tighten the bushing without preloading the bushing by twisting the transmission.
(2x per side) 13mm transmission mount bolts: 17 ft-lb
(1x per side) 16mm bolt/15mm nut: 37 ft-lb
3x 10mm heat shield bolts: 7 ft-lb
Note:The tricky part is aligning the transmission mount without preloading the bushing to the subframe. You can also stiffen/extend them without causing excess vibration by removing the mount, cleaning it, and putting hard window caulk or soft urethane into all the empty spaces in the mount.