2009 S80 T6 AWD Rear End Noise

grimey001 · Post by **grimey001** » 13 Apr 2015, 17:40

Hit 128,000 mi and developed a roaring noise from the rear end. Immediate thought was wheel bearing, replaced both and still roaring. Now the attention shifts to the differential, which costs over $4k just for the part? IF, this is in fact the problem, rather than replacing the rear chunk, can I simply remove the rear driveshaft and make it a FWD car? It's 95% FWD anyway. Can this be a practical fix to a very expensive repair? Will this affect ABS or any other functions/sensors on the vehicle?
Or am I missing something simple, like the Universal joint on the driveshaft failing?

fishman · Post by **fishman** » 20 Apr 2015, 19:22

Are you kidding me.
Last week my 2008 s80 awd t6 had the exact same thing at exactly 128,000 miles.
Took it to the volvo dealer and they said needs a complete rear differential, at a cost of $6,000.00. This car has been babied and cared for perfectly.
Called volvo and they said to go pound salt. I believe volvo knows there is an issue with the drivetrain but is trying to avoid an expensive recall.
Any suggestions?

Post by **jimmy57** » 21 Apr 2015, 05:59

The rear differential bearings can be serviced. Volvo doesn't service them but they are common bearings used in multiples of other car lines as wheel bearings and transmission bearings. I have rebuilt 2 already and both are quiet 20,000 miles or more later. Both of these vehicles had low lube oil level in the differential when they failed.
The shop will have to make an extra long socket for the pinion bearing retainer nut. There are no Volvo special tools for this diff unit.
Volvo does service the seals for the unit. There are two axle seals and the seal for pinion shaft that is a double seal as it seals AOC oil in its area and diff lube into the diff.

dodenhoff · Post by **dodenhoff** » 27 Jul 2015, 20:24

2007 FWD with 120,000 miles roaring noise. Rear wheel bearings I hope despite having similar noise. Hope not transmission.

dodenhoff · Post by **dodenhoff** » 23 Sep 2015, 21:29

You probably already have checked, but swap tires front to back and see if noise clears up. Bad alignment from factory can cause serious cupping and once the cupping starts, it only gets worse. I only wished I followed my own advise before replacing hubs anyway.

I'm curious though since I have similar millage, did the replacing differential make noise go away?