2002 325xi 5th gear vibration / grinding

[tramontane]

2002 E46 325xi
211,000 miles
Auto tran

Regularly maintained, tranny fluid change, gaskets etc about 50,000 miles ago.

Ended up getting the dreaded guibo vibration on acceleration. Replaced center driveshaft bearing (completely shot and rubber torn out, only bearing and metal left) and the guibo which had some wear on it, but not nearly as bad as I have seen on the forums. Went to replace tran mounts until I realized its one mount in the case... ill go to the shop for that one!

A day later after that change, the car drives so smooth and flawless up until 5th gear. I get a very noticeable vibration that is giving me a nasty headache on the road without the radio on. I did my best to make sure the driveshaft was aligned the way I found it, so I'm hoping it isn't a driveshaft imbalance... Put it in 4th gear and went to that speed, and it is smooth without vibration. Remains in 5th...

Any ideas? Tires are fairly new. Nothing was changed except for the completely shot center driveshaft bearing and the guibo.

Also completely unrelated (I think) I get a weird vibration ONLY under acceleration in hilly areas. Also trans related?

EDIT: I would also like to add that my transmission/clutch is starting to stick on cold mornings. If that is relevant... Gets better about 3 minutes into driving (read that the springs dont go back into place as easily since its old?)

Thanks

[dworthy]

If the center support bearing and guibo were shot, then the driveshaft is too. If you have more than 150k on the car a new shaft should have been the answer as your u-joints have gone bad due to the excess slack from the CSB.

[tramontane]

If the center support bearing and guibo were shot, then the driveshaft is too. If you have more than 150k on the car a new shaft should have been the answer as your u-joints have gone bad due to the excess slack from the CSB.

U joints were pretty stiff and only moved in the directions they were suppose to. No weird noises or movements from any of the 3 points. No rust or odd rub marks either.

Would an imbalanced shaft cause it as well? I marked the spot before I disassembled, but if it was even slightly off, could that cause it?

[bmwdirtracer]

"Slightly off" can be just as bad as "way off", where driveshaft balance is the concern.

When a center support bearing fails, it's a sure sign that the driveshaft has an additional failure; either a universal joint, or a CV joint. U-joint failure is usually proven by finding a notchiness at one point in the travel; "stiffness" would be a bad thing, not a good thing. Flex-discs (giubos) don't generally cause vibrations under acceleration, until they are coming apart. The center support bearing and driveshaft u-joints do, however.

My feeling would be that you need a driveshaft; I have never seen a CSB replacement work for more than a couple of months.

That said, the transfer case can cause vibrations, as can a bad halfshaft; both are known failure items on "x" cars.