Dear Brickboard,

I just finished replacing the differential seal on my wife's 1990 240 DL because it was leaking rear end fluid. The job seemed to go smoothly.

Unfortunately, the rear end whines now. It does it mostly when deaccelerating. When I give it the gas the noise stops.

It never made a rear end noise before so there is no doubt that I screwed up.

By the way, it does not seem to leak a drop now (big consolation, right?).

I was not careful in making sure that I mated the differential flange to the drive shaft flange on in the exact holes it came off of. I hope that is not the problem.

I was careful to use a puller to pull the flange of the shaft.

I have read that the flange nut torque is important. When I put the flange back on, I just pushed it on the spline and then used the nut to pull it on. I marked the flange nut position before I loosened it and then tightened it to the mark since I have read that the nut torque is important.

Once I got the old rusty seal out, everything behind it looked good and clean. I carefully tapped the new seal in place and it felt like it seated nicely.

Finally, I filled the differential back up with 80-90 weight differential oil.

Do any of you have an idea where I went wrong? Please advise. Thank you.

2OldVolvos