Driveshaft center support bearing

[ccb222]

1987 Volvo GLE Wagon, Automatic Transmission.

I recently replaced the driveshaft center support bearing which remedied the serious vibration I was experiencing.
The bearing was seperated from the rubber, and obviously "catastrophically failed".

NOW, however, there is an audible "moan or whine" when under way. The sound is pretty consistent regardless of speed and with the radio on it can't be heard. I know this isn't right, though, and I'm looking for the "fix".

I have inspected the transmission mount which I think is fine.

Is it possible that the bearing housing that bolts to the plate below it, or the plate itself, need to be adjusted in position?
This seems to be possible because the bolt holes are over-sized, but it would be a trial and error operation, I think?

Suggestions will be very much appreciated.

Charles

[jimmy57]

Is the driveshaft phased properly?
The shaft must be put together with the u joints in the proper relationship. There should be stamped lines on that vintage shaft on the two pieces at the slip joint area. They are stamped after its painted and usually the marks are rusty. The middle and rear joints are 90 degrees offset. UJ's speed up and slow down as they move when there is any angularity. TO assure no vibration the two are offset 1/4 turn so the speed changes cancel each other.

[ccb222]

I assume that "phasing" the driveshaft is the reason the manual instructs to mark the positions of the U joints before taking them apart, which I did, and I reassembled using those marks. However, it seems possible that it was "out of phase" in the first place and that could have caused the center bearing failure. What do you think?
In any case, I'll take a look for the markings you mentioned and will report back.
Thanks for this suggestion---