E46 M3 Transmission Mounts
While my goal is to build a nationally competitive autocross car, I am also focusing on making improvements to the car that make it more enjoyable to drive on the street and at the track. One of the mods I had identified early on was a change in transmission bushings, in my E36 this made a substantial difference in feel.
Wolfe's DIY Transmission Mount Thread was a great resource and demonstrates how simple and straightforward this mod is. It took me about 45 minutes on jackstands in a driveway with manual tools, with a hoist, transmission jack, and power tools this would be a 15 minute job, it really is that easy.
I decided for this car, the
E46 M3 Transmission Mount (2x Part # 22-32-2-282-340) was the right balance of performance improvement and street manners. I had AKG Poly mounts in my E36 and while they dramatically improved the stock transmission's movement in corners, the increase in NVH would be unacceptable for a daily driver.
Left: New E46 M3 Mount, Right: 60,000mile 128i Mount
The mounts look somewhat similar in photos (the longer stud on the E46 mount is no issue at all and they share a thread pitch so can re-use existing hardware). However, there is an easily noticeable difference in stiffness just by even squeezing them by hand.
Impressions:
I have only driven a short distance so far, so I will update this in a few weeks once everything has settled in and I have a bit more time on them. However, at first glance, I noticed virtually no NVH difference, perhaps an absolute tiny bit at idle, but really nothing of consequence. However, in the first corner that I tried a 2-3 shift, it was immediately obvious something was different, in the best possible way.
According to Wolfe's thread, I definitely overtorqued the nuts that hold the mount to the transmission and brace (not having read that section in time) and that may contribute to higher than necessary NVH, but so far, that has been a non issue.
Considering the parts are less than $40usd and it takes less than an hour to install, these are a great value and an awesome way to improve the "feel" and experience of driving your 1 series for a reasonable price. Highly recommended.
Mark
Teaser for next week...
