Porsche Cayenne (955) Transmission Mount Replacement January 24 2020
While having a shop perform a wheel alignment on our Cayenne S, the tech pointed out a worn transmission mount. It was time to replace the mount, and we'll show you how it's done. The job is not too difficult. First, get your Cayenne safely in the air. We will assume that you know how to safely lift and support the vehicle. If you use the air ride suspension to lift your Cayenne to maximum height, we still recommend jack stands, as the air suspension system can still fail and lower the vehicle onto you.
This is the transmission mount in question. This view is looking forward.
Here is a close-up of the transmission mount. 2 bolts attach it to the transmission.
We are going to remove the entire transmission crossmember, so we will need to remove anything attached to the crossmember. Remove the two bolts that attach the splash shield to the transmission crossmember.
Before we unbolt the transmission crossmember from the chassis, we will need to support the transmission. We used a scissor jack on top of a beefy vacuum chamber we had lying around. We aren't trying to raise the transmission, but just support it. Just have it touch and no more. A bottle jack could also work instead of a scissor jack.
With the transmission supported, you can loosen the 4 bolts holding both ends of the crossmember to the chassis and the 2 bolts holding the mount to the transmission. Pro tip: don't smash your face when the crossmember drops from the chassis.
This is the crossmember removed from the vehicle. Note the orientation of the mount so that you can install the new mount properly.
We put a metal disc over the mount to aid in pressing out the mount. Our shop press easily pressed it out.
This is how the transmission crossmember looks like with the mount pressed out.
We bought a Corteco brand mount, and we found that the mount was too big to fit in the transmission crossmember. We had to aggressively chamfer the edge of the mount on a belt grinder in order for it to be pressed into the transmission crossmember. The photo shows the mount after a few rounds of grinding and test-fitting, but we ended up having to chamfer the mount even more aggressively than shown. Once the mount was able to get started in the hole, the press was able to force the mount through the rest of the way. We'd again like to remind you to make sure the mount orientation is correct before pressing it in.
Having to chamfer the mount took some time and it would have been even worse if we didn't have a belt grinder. We're curious as to whether other mounts from other manufacturers fit without having to chamfer the edge. We'd love to hear about your experience in the comments below.
Re-installation is the reverse of removal. Make sure you use new bolts to attach the mount to the transmission. The bolts can fatigue over time from cyclical loading, and Porsche recommends replacing these bolt whenever the mount is replaced.