Vibration

[Sadgrandad]

1992 525i SE (auto), 215k miles. I replaced my prop-shaft (driveshaft) donut coupling when I bought this car 3 years ago. Recently, my friendly local mechanic (GM franchise) replaced the shaft's centre bearing as the housing had fractured. After he did the work, there is a quite harsh vibration - from about the centre of the car - under load from a standstill, like when you give it some throttle. I thought he must have failed to tighten the centre bearing housing bolts, so I gave it back to him. He has checked all the fastenings that could be involved and everything is tight. Any ideas?
Rod

[632 Regal]

needs to be inspected, might need a new driveshaft.

[Sadgrandad]

Problem is, nothing looks wrong with it - there's a minute amount of play in the rear (to diff) joint. I thought it might not have been put back in the same position as it was taken off, making it out of balance, but would expect that to make it vibrate more. It only vibrates under high load in 1st and then only for a short time. You drive thro' it and it seems OK, certainly up to 80 - 85.
Rod

[Warren N.CA]

Sort of a "notchy" effect around the center. This, too, can cause vibration. Also, check for proper preload of the CB (See Bentley.).

Problem is, nothing looks wrong with it - there's a minute amount of play in the rear (to diff) joint. I thought it might not have been put back in the same position as it was taken off, making it out of balance, but would expect that to make it vibrate more. It only vibrates under high load in 1st and then only for a short time. You drive thro' it and it seems OK, certainly up to 80 - 85.
Rod