Noises can tell us a lot about car problems. Some may indicate that rear differential repairs are needed.
One technician recently installed a new rear differential on a 1998 Pontiac Firebird. The car was brought in when the driver noticed a rotational noise from the rear.
At first, we thought the universal joints — also known as u-joints — were the culprits, because they were older and dried out. U-joints connect different parts, such as the driveshaft and rear differential.
Replacing them, however, didn’t fix the problem.
After further investigation, we decided that the rear differential needed to be replaced.

What is the rear differential?
The rear differential sits between the rear wheels. It takes rotational energy the drive shaft creates and splits it to the wheels equally.
In this article we published, we talk about how you can prolong the life of your differential and some signs it’s going bad.
We replaced the rear differential in this situation, but we also do rear differential repairs.
Other sources of sounds
Sometimes axle bearings on the rear axle can go bad and make a growling or humming sound. That sound can depend on the type of vehicle and whether it’s coming from the left or right side of the vehicle.
The carrier bearings, which are attached to the ring and pinion, is a noise that people will hear in the car, especially if the pinion bearing is going bad.
The pinion bearing is near the front of the differential, and that is where the driveshaft and the yoke of the differential connect. That’s also a common place for the front pinion seal to leak.
Another common problem is where the rear axle shaft seals begin to leak. It’s possible on some vehicles where the differential fluid could be slung around and actually get on the brake pads and rotors.
This may reduce your braking ability — and in extreme circumstances — could catch on fire. Normally, you would just see smoke coming from the wheel, and it would stink.
Clutch packs, which can be found on some limited slip differentials or posi track differentials, can also cause some noise.
HomeTowne Auto Repair & Tire is an authorized Michelin and BFGoodrich tire dealer located in Woodbridge, Virginia. Automotive repair services are performed on all makes and models, including oil changes, brakes, alignments, inspections, and computer engine diagnostics.