Replacing the transmission mounts

I noticed that one of my rear transmission mounts was saturated with thick oil; it was also misshapen and very soft. I decided that replacement was necessary in order to protect the tranny and driveshaft. The following instructions are for a 1986 325es with a manual transmission. Note, these instructions should be very similar for a 318i or 325i with a manual transmission.

Cost of mounts is roughly $13-18 each.

The two rubber/metal mounts are located at the back of the transmission where the drive shaft is bolted on. They are attached between the transmission and a support bracket.

• 1. Jack up the car in both the front and rear and place on jack stands; make sure the car is stable.


• 2. I suggest that you degrease the area around the mounts to protect the new ones. You should also check to see if there is an oil leak that needs to be fixed.


• 3. Place a jack under the back area of the tranny to support it when the mounts are removed. I suggest placing a block of wood on the jack plate in order to protect the transmission.


• 4. Lower the exhaust. This was necessary to allow access to the mount's bolts on my car. I removed the rear hanger and unbolted the support that attaches to the transmission. This may vary depending on the model of your car.


• 5. Check to make sure the tranny is supported before undoing any bolts. A 13mm socket and 13mm wrench is necessary to complete this part. The order in which you remove the 6 nuts is not crucial to the job, but rather it is more convenient to start with the top nuts that attach the mounts to the tranny, next the mounts to support bracket, and finally remove the support bracket. I had to use a 13mm wrench to remove the top bolts because there was not enough room for a socket wrench. None of the bolts were very difficult to remove. The height of the transmission should not have changed significantly throughout this process.


• 6. Once the support bracket and mounts are removed I suggest degreasing and cleaning the bracket. This will prevent oil from contaminating the new mounts.


• 7. Attach the new mounts to the bracket. There are indentations in the rubber that force you to install them correctly. The top bolt enters the U shaped mount on the back of the tranny first. The raised circle should point towards the rear of the car.


• 8. Torque the nuts using specification found in your manual and visually inspect the mounts. If everything looks good slowly lower the jack just in case you made a mistake. Reattach your exhaust and go for a drive.

My mounts were heavily worn. When removing them I could feel them flex while unbolting everything.
The new ones are considerably more solid and have stopped some of movement in the driveline.


Mark Distelhorst