bad vibrations...ahem

[badvibrations]

I didn't know where to put this.

This problem slowly developed and seemed to get worse over my recent 1500 mile road trip. And continues to get worse now.

I have a high frequency vibration at 60-70mph. It seems to diminish below and above that speed range. Also it seems to be more intense during open throttle in gear operation(cruising and acceleration). Though it is still there during depressed clutch/neutral operation.

My guibo, and CSB are fairly new and still appear that way.
My engine and trans mounts are IE poly style and not new but appear to be solid and sound(the vibration is new and wasn't there after installation of the poly mounts).
I think that covers it all...

The vibration seems to be too high Hz for it to be being caused by wheels and tires unless I have one that has two high spots on it.
I am leaning towards u-joints, rear subframe mounts, difff mount, or diff itself.

Any opinion is well appreciated.

thanks

[bmwE30/541]

i have the same problem besides mine starts between 45-55 after that it goes away. Feels like it is in back right of the car most of the time my u-joints and bushing are all good subframe seems to be good, but i cant figure it out.

[badvibrations]

r3ally?
anything?

bumpidy bump

[jlevie]

That could be a bad drive shaft. If the CSB required replacement and the drive shaft wasn't replaced at that time, the odds of the drive shaft being the cause go way. in almost all cases a failure of the CSB will be caused by binding u-joints in the drive shaft. Both should always be replaced at the same time.

[badvibrations]

thanks,
now would this be seized u-joints or too much free play in the u-joints or either.
just for curiosity's sake.

[jlevie]

I've never seen loose u-joints on a BMW. Probably because they suffer from lubricant failure and bind up and then get replaced before they wear enough to be loose. But either will cause vibration at speed. The only way to assess the condition of the drive shaft is to get it off the car and move the u-joints around, comparing the way those feel with how the u-joints in a new drive shaft feel. but as I stated above, if the CSB has failed you can take it as an article of faith that the u-joints are bad.

[87-325ic]

double check your guibo. i replaced a driveshaft and everything. to find the guibo was trashed a month later... so double check it.

check the balljoints on the tie rods too. i have a nasty vibration due to that right now.

[badvibrations]

double check your guibo. i replaced a driveshaft and everything. to find the guibo was trashed a month later... so double check it.

check the balljoints on the tie rods too. i have a nasty vibration due to that right now.

Already checked the guibo, as stated in original post. It's fine.
If the tie rod ball joints were bad I would have a steering wheel shimmy and not a torque related vibration.

Thanks for the info and opinions guys.
I'm changing out the driveshaft in a few weeks.
I'll post again after said job is completed.