Wierd shaking at different speeds.

[Doughnut]

My 323i shakes at 80kmph and upwards however i dont believe that it has much to do with my cars alignment or wheel balance because when i take my foot off the gas pedal it stops shaking.

One of my two rear rubber transmition mounts is completely ripped in half, (in process of sorcing new mounts) but my question is,

Is this broken rubber mount causing my car to shake when im on the gas pedel?, my car does not shake when it is stationary.

my car is a manual, sorry for long post, any help is much appreciated.

 

[Kirby]

It certainly could cause the shaking. Think about the torque that is transferred to the rear wheels. The drive train transfers that torque. If the drive train is sloppy, some of that torque gets transferred elsewhere.

 

[Doughnut]

new pair off rear gearbox rubber mounts bought... $102.00 Australian dollars
Ive gotten a wheel alighnment and wheels balenced, but was only 3 degrees out and the wheels didnt need much weights put on at all, it still shakes the same amount
Hope the mounts stop the shaking,

Fingers crossed :S

 

[E30m42cab]

how are your rear sub-frame mounts?

 

[Doughnut]

They are brand new!
The cars original owner put an reconditioned engine in, but they must have reused the old rubber mounts on the back of the gearbox (lame mechanics) and replaced the sub frame,
no worries

 

[Doughnut]

after replacing the gearbox mounts the car still shakes at 80km/s upwards, then stops after 100km/s on and off the accelorator makes it shake and then not shake?
Please dont tell me this is engine mounts.... upon inspection of the engine mounts (up front) they look and feel ok.
Thoughts anyone?
Cheers.

 

[E30m42cab]

maybe the guibo?

 

[Doughnut]

Ok, just what is a guibo... are you making up words on me E30m42cab, I have a feeling it may be the tail shaft out of balence, or the diff..... *errrr*

Tell me its something simple

 

[AWD_Guy]

trailer arm bushings?

 

[E30m42cab]

No, I'm not making up words. The guibo aka a flex disc... its a rubber disc that connects the driveshaft to the tranny (and it's a pain to get off).
http://realoem.com/bmw/showparts.do?model=BA73&mospid=47325&btnr=26_0009&hg=26&fg=10 (part #2) Your trailing arm bushings might be the culprit, but that would throw the wheel out of allignment. I'll bet it's either the guibo or a driveshaft bearing. That broken rubber tranny mount may have hurt the guibo.