The stock center support bearing carrier holds the driveshaft in place with rubber so thin about 20 lbs of force moves it from center to the end of its travel. While that’s great for making sure no NVH makes it to the cabin, it doesn’t keep the bearing centered well under load, allows the bearing to sag over time and ruin the driveshaft alignment, and creates slop in the driveline during shifts and throttle application. Over time the OEM bushing sags and becomes brittle, eventually dry rotting and cracking. Even on the best-kept cars, the stock bushing can start to from cracks in as little as 5-10 years. When the bushing lets go, it can lead to excessive vibration and clunking, and put more stress on the bearing. To make matters worse, the stock carrier is molded onto the center support bearing, so it’s not easy to replace without special tools.
The first video below was recorded on an Audi, but BMW (and everyone else’s) OEM carrier design is similar. The shaft is not well-supported by the soft OEM carrier, so it’s allowed to travel off-center during rapid loading and unloading. The second video is a BMW carrier showing a comparison of how much the OEM carrier gives under load and the improvement with the JXB carrier.
This upgraded unit keeps the driveshaft firmly in place at all times, and its solid construction ensures it will never wear out. The thick bushings ensure the driveshaft cannot move from center, maintaining driveshaft alignment at all times.
Two options are available for the bushings, both of which are many times over better than the stock bushing. We’ve paid close attention to the NVH levels associated with this upgrade. After extensive design iterations, we’ve come up with custom isolator bushings that separate the carrier from the body of the vehicle and mounting hardware. These carriers substantially reduce NVH levels.
The street bushings absorb most of the NVH from the drivetrain. Some light NVH is possible at some speeds in the form of a soft hum. With a modified exhaust or windows down you’ll probably never hear it.
The track bushings are for those who want no-compromise drivetrain performance. These may create a substantial amount of cabin noise. Not sure which is for you? They’re interchangeable so you can try them both.
Installation doesn’t require removal of the driveshaft. The 2-part design clamps around the OEM bearing. The old carrier must be removed, so a cutting tool is required. Below is the installation of this part on an E93 335i. The exact steps to access the carrier will vary slightly by model, but the removal and installation of the new carrier is the same. The basic steps are:
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Remove any braces or splash shields preventing exhaust and heat shield removal
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Remove or lower exhaust in area of center support bearing
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Remove heat shielding covering center support bearing
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Cut off OEM carrier and remove center rubber rib with razorblade, leaving base layer of rubber intact
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Clamp new carrier around OEM bearing
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E84 X1
