My 89 745T has developed a low rpm, low speed drivetrain vibration. It sounds as if it is coming from the driveshaft. I think that it began after I drove down a road that was being paved and some loose piece of metal caught on something under my car briefly. The car sort of shudders a bit while rolling along in drive at under about 25 mph. It runs smoothly at higher speeds, including highway speeds. I am not sure whether it is rpm or speed based; both are low when I am aware of the shudder or vibration. I think it occurs whether the trans is in 1st, 2nd or drive.

Thanks for any input.

Philip Bradley