Had some time to sit down and install our new urethane transmission mount for one of our 350Z’s. This mount is a billet aluminum casing, and we offer it with 3 grades of urethane – 60a (comfort), 75a (sport) and 90a (race). We used the 75a for my car.
To start off, use the factory recommended jack points front and rear (see picture 1). With the car up in the air, your first thing is to remove the factory transmission cross member. This is a black steel beam that runs the width of the transmission (see picture 2). To loosen the crossmember from the chassis, there are 4 x 14mm bolts. You’ll now see the transmission mount, attached to the underside of the transmission (picture 3). Next, you will remove the long gold bolt/spacer from the stock transmount, which runs through the crossmember. To gain better access to the bolt, we found it easiest to remove the Y pipe, as it makes things. Since mine has been in there for a few years and I had noticed a bit of an exhaust leak recently, I took this opportunity to replace all the Y pipe gaskets and kill 2 birds with one stone. Take a jack, or jackstand, and place it under the transmission to keep it from sagging. It is still attached to the engine at the bellhousing, as well as the driveshaft, but you don’t want any accidents! Finally, remove the 2 x 14mm bolts and the transmission mount comes off the transmission. Fitting the new mount is just a direct reversal of the above process and goes right in.
So what does it feel like – HOLY SHIT stiff! The car immediately has a much deeper tone inside the cabin just by virtue of the fact that the new mount has much less slop in it, and has a full radius bushing (if you look in the picture showing the side by side with the stock mount, you can see daylight!). It was so much different sounding I thought my Y pipe was still disconnected! The shifter has a much more positive feel to it, which is very noticeable especially at higher rpm shifts. Engaging first and running through the gears from a dead stop, you immediately notice that the car has a much more direct overall feel. If you are in a higher rpm and just crusing (for example 2nd, entering a turn) the slight rocking back and forth that the car used to have is completely gone. I’ll drive the car through the weekend provided the weather is nice and post any noticeable changes.