I just finished replacing the rear wheel bearings in my 240 DL SW, 1985.
Thanks to all that wrote about it before me, as usual the BB is of great help, and in no small measure the reason I enjoy my old Volvo, THANKS.
I had read what I think might be everything ever written about the subject on the BB, However, one thing I noted that I had not read about.

I replaced the bearings because they were noisy, they had failed. Upon driving the car with the new bearing all sorts of other rear end noises that I had heard before but could not trace had gone away. Much to my surprise, rattles and clunks were eliminated, not just the obvious grinding noise of a failed bearing.

I am delighted and I though this might be of use to others who, like I had done, keep chasing rear end noises to no avail. Consider the rear wheel bearings.