It appears my wagon has a noisy diff. It has a very noticeable whine on accelerating from 95-100km/h, but it can be heard at very low speeds too -- such as when turning into my driveway. It is longstanding, and I have changed the driveshaft centre support to rule it out. I had an indie Volvo mechanic spend some time trying to diagnose. He could hear the noise when driving, but not when running the car up on the lift. Rear wheel bearings and wheel alignment are apparently fine. Putting the auto gear selector in neutral (at low speeds) doesn't stop the whine.
So I'm considering my options. I don't want to change the entire axle. I thought about trying to source a good used diff, but I plan to keep the car as long as possible, and having it converted to electric when the time looks right and i have the (quite substantial) funds. Can anyone tell me which of the locking diffs from VPN below will fit? Only one is specifically listed for Volvo. The Powertrax is cheaper and maybe won't have issues with the speed sensor strip not going all the way around and having to shim the sensor.
Thanks!