In Reply to: Beg to differ, the bolts in the guibo do not posted by Bill R. on August 29, 2001 at 08:51:45:
Must have been the late night out with the local bimmer group. Sorry again.
directly tie the driveshaft and output flanges together. Three bolts come through from the driveshaft side and attach only to the guibo and three bolts come through from the output flange and attach only to the guibo. There is no direct metal connection such as bolts running from flange to flange. The guibo absorbs stresses in both directions, thats why it has directional arrows on them. If installed in the wrong direction the guibo won't last long at all. And yes the driveshaft can separate completely with a bad guibo.
A bad guibo will not cause the problems you are seeing. There is not that much torsional flex in the guibo.
The guibo absorbs mostly lateral stresses. (Diff moving up/down relative to the tranny.) The torsional stresses are reduced due to the metal sleeves running through the guibo and tying the tranny output and driveline flanges together.
The bad guibos I've seen start to shred fabric that is embedded in the rubber. I suppose they could fracture, but I've never seen them fail that way.
Surging implies (to me at least) that you have a fuel problem. Does this happen at higher rpms?
Drove a '90 535i with 109k miles. Under hard acceleration, there was a surging sensation in 1st and a little less in 2nd that WASN'T the engine. My '70 Camaro does the same thing becasue the ring and pinion are worn and a little loose. I've driven 6 5spd BMW's and none of the others did this.
My hope is it's the guibo (rubber donut?) I hear BMW's have, but have never seen. If I put the car up, can I crawl under and move the draft shaft around and see if the guibo is going bad?