Vibration under acceleration

worn carrier bearing causes exact symptoms, replaced mine...all gone

Originally Posted by ///M3AN-MIKE

worn carrier bearing causes exact symptoms, replaced mine...all gone

worn carrier bearing you mean the CSB? The thing that supports the driveshaft?

If so, I replaced that and still have the vibration that the OP describd only mine is a 5speed.

Originally Posted by ///m3an-mike

worn carrier bearing causes exact symptoms, replaced mine...all gone

+1

Originally Posted by grubby_baker

... I did 'preload' the carrier bearing by pushing it toward the rear of the car as it shows in picture in the Bentley, even though it says in the text 'push toward the front'.

I don't think the CSB should be preloaded by pushing it to the rear.

I believe it is correct to do as the Bentley *text* states, "...by pushing the bearing forward 4-6mm from center."

I researched the reasoning for preloading. I found an explanation I liked (in the E39 section of bimmerfest): "...when the car is lowered, the Rear Differential moves upward ... and ... the Driveshaft moves forward a few mm."

The reasoning goes on to say that preloading would not be necessary at all if the CSB is bolted down when the car is resting on its wheels, as when a mechanic works from within a pit, over which the car was driven.

Bentley has confused things by showing an "xi" rear driveshaft without labeling it as "xi" (see DRIVESHAFTS 260-5 in Bentley, which the reader would assume to be a RWD).

The word "center" is confusing too. Center in relation to what?

From the Bentley photo, I am guessing that the oblong holes in the CSB mounting bracket would be "centered" if the bolts sat in the middle of those holes. However, the photo clearly shows the CSB pushed toward the "front" of the car (top of photo). The bolts are clearly off-center in the oblong holes.

The reasoning makes sense to me so I wanted to share it here.

OP: Sorry for this late information. I just found it today--I'm going to pull my own drive shaft very soon (for flex disc, csb, etc) and wanted to get my ducks in a row. I've gone cross-eyed with all the reading and sorting truth from fiction but I've think I've got it now.

Images are from realoem 1) 325i driveshaft, 2) 325xi driveshaft

Thanks for the background/feedback, Latitude. The car has seem to be doing fine since I have installed the new driveshaft. We are now only experiencing a clunk from the passenger front side when going through a crappy parking lot. It might be engine mount or strut? The engine doesn't move a lot when you press on the pedal in park (like on YouTube). I'll start a new post.

Originally Posted by grubby_baker

Thanks for the background/feedback, Latitude. The car has seem to be doing fine since I have installed the new driveshaft. We are now only experiencing a clunk from the passenger front side when going through a crappy parking lot. It might be engine mount or strut? The engine doesn't move a lot when you press on the pedal in park (like on YouTube). I'll start a new post.

If you hear a clunk during parking lot type of driving (slow speed?) then I would assume its your swaybar link.

Had the exact same issue, fast speed I wouldn't hear a thing, slow speeds I could hear it. Turned out to be swaybar link in the front