I have a faint whistling noise coming from my 240's driveline at speeds above 20mph or so. It increases with speed and it still there with the engine turned off and the tranny in neutral. However, it disappears when accelerating - it's only there when coasting or decelerating. Is this the center support bearing? The bearing *seems* tight, though the rubber donut had spun in the housing a bit, so the support spring was horizontal instead of vertical. I removed the bottom of the housing and reseated the spring - no change in the noise. Does this sound like a center bearing problem and how difficult are the things to change? It was last changed about 2 yrs. ago to a Scantech item. The rear axle seal and outer pinion bearing were also replaced then, but I bought the genuine Volvo parts since rear axle failure wasn't something I was willing to deal with.

I changed the diff. and tranny oil - no change in the noise and no significant metal shavings in either (a few flakes of metal but no more than I've seen in other cars).

There are also occasional "popping" noises when moving off from a stop. The rear axle bushings are also 2 yrs old and in good condition...

-b.