Volvo Grinding Noise While Driving
About a week ago we received a call from a long time customer saying that he hears a noise coming from the back of his Volvo XC90 when driving down the road. We didn’t think much of it because wheel bearings are a common Volvo Repair and they could give him the noise that he was describing. We definitely had the wrong assumption.
When the vehicle came in the customer said that there had been a warning light lit up on his dash for about a month but since the vehicle seemed fine he didn’t bother to call for an appointment. We attempted a road test the vehicle but the noise was a loud grinding that could be felt throughout the entire vehicle as the wheels turned. One of our Master Technicians immediately pulled the vehicle into the shop rather than take the standard road test. We just didn’t want to potentially do any further damage than was already done. When we pulled the Volvo into the shop we hoisted it on the lift and saw a large amount of fluid all over the rear portion of the underside of the vehicle.
It didn’t take long to see that the rear differential (in short, a differential is the gears that turn the wheels) was literally split in half. Since there wasn’t any way to know what caused the damage
without removing and disassembling what was left of the Volvo Rear Differential and it had to be removed to be replaced, we went ahead and removed it. It was fairly involved but we got it out without much of an issue at all.
Once we got it out we took it apart for inspection to find out what had failed. There is a bearing in the rear differential called a “Pinion Bearing”. This bearing started to go bad and over time completely failed. This caused the gear that the bearing guides to move around allowing the main gear in the differential to rub on the inside of the differential housing until it eventually banged against it hard enough to break it in half.
Since the housing and gears were all completely destroyed we ended up replacing the entire differential unit. Then we performed an alignment because most of the rear suspension had to come apart to remove the old differential and to install the new one. The part was special order and took a few days to come in but the customer ultimately had their vehicle back in their possession within 2 business days.
When warning lights show up on your dash, it’s never a good idea to ignore them. This differential is equipped with a fluid pump on the differential that’s controlled by a computer that’s also mounted on the differential. The computer had shorted out internally causing the pump to malfunction. This caused a great deal of heat which ultimately caused the pinion bearing to fail.
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I’ve been going to James since his first shop opened over 10 years ago. I was happy to use him then and I’m happy to use him now. Always professional and honest. The pricing is also more than fair considering the service you get with anything that they do. Great spot and great people.