Ok,

I have a 00 xc70 with 198k. I replaced the driveshaft about 40k ago and the angle gear shortly after. Lately I had a clanking/clunking metallic sound coming from the rear of the car ONLY when coasting under 10mph. This noise would disappear when torque was applied and then disappear completely after 10-15 minutes of driving. It would not matter whether the car was in drive or neutral. THEN yesterday I was decellerating down a hill and a loud CHUNK noise came out of the rear and all noises have ceased. This all occurred after a successive LR and RR tire failures and I had to drive on the donut. I've heard stories about the Viscous clutch problems with mismatched tires, could this be it? Any help appreciated

 

Yes.

 

+1 Mismatched tires can cause all sorts of issues if used for extended periods. I always wondered why Volvo puts a mini spare in AWD vehicles anyway