[jeddo45]

Hi community

Trying to figure out what could be the issue with my car. If I push the car to about 95 miles an hour, a nasty vibration starts from what I think is the back/ center of the car. Once the vibration starts, I have to slow way down for it to start. It doesn't matter what gear I'm in once the vibration starts, I have to slow down to about 35 miles for it to stop. Then I could go up to regular speed but obviously not to that 95 mph threshold.

I know on my dad's 750i when his Guibo was going bad, it was more of an immediate clank once you engaged the throttle then vibrated, so I'm not sure if my issue is the same.

Thoughts? Any help appreciated.

[tlow98]

Guibo is pretty easy to inspect and cross off the list.

I’d get under there and check it out first.

[Efthreeoh]

My suggestion is to inspect the driveshaft center bearing. The guibo really would not create a vibration unless a chunk of it is missing, which wouldn't happen anyway.

To inspect the center bearing, you need to remove the aluminum heat shields guarding the exhaust to expose visually the driveshaft, then with the transmission in neutral, rotate a rear wheel and observe the movement of the center bearing in its rubber mounting bracket. Also, the driveshaft u-joints have very tight tolerances for "play", like .004" IIRC. High speed driveshaft rotation with worn u-joints can produce vibration as well as the center bearing.