E46 M3 Clunk After Guibo Replacement & CSB Dropped

[BinBuilt]

I recently replaced the guibo on my E46 M3 and dropped the center support bearing during the job, but I never fully removed the driveshaft. Ever since then, I’ve noticed a clunk/chatter from underneath the car on initial takeoff, when reversing, and sometimes while slowing to a stop. I’m not sure if it’s related to the CSB or something else. Has anyone experienced this or have ideas on what I should inspect first? Any help would be appreciated.

[sapote]

Did you have the drive shaft supported when the CSB was dropped or let it hanging cantilevered on the U-joint? Unsupported can cause the damaged Ujoint.

[BinBuilt]

Did you have the drive shaft supported when the CSB was dropped or let it hanging cantilevered on the U-joint? Unsupported can cause the damaged Ujoint.

I left it hanging but it was hanging on the heat shield

[bigjae46]

The CSB has to be preloaded. I'm pretty sure the CSB needs to be pushed forward against the body studs and then torqued. Or the CSB is bad. Sometimes unbolting a marginal part will accelerate failure.

Unless you were trying to pull or yank down on the driveshaft while it is unsupported, I doubt the U-joint would go bad. If it did go bad...it was going to fail soon anyways.

[sapote]

No preloaded CSB won’t cause clunk noise until the rubber ring holding the bearing torn.

“I left it hanging but it was hanging on the heat shield”
im surprised the thin AL heat shield can hold the heavy shaft. I don’t know how high car jacked up, if the shaft front tip not resting on ground then not the heat shield that stopped the shaft from going lower but the rear joint was at its limit and the cantilever weight of shaft had damaged it.