Truck differential repair

Rear ends, carriers and drive axles on medium and heavy duty trucks, from a leaking pinion seal to a complete carrier exchange.

A differential usually tells you it is failing well before it stops the truck: a whine that changes with throttle, a clunk taking up slack, or gear oil on the inside of a wheel. Caught early, a lot of that is a bearing, a seal or an adjustment. Left until it locks up, it is a carrier and sometimes an axle housing.

What we see most

• Whine or howl that gets louder on the throttle or on coast, typically ring and pinion wear or setup
• Clunk when taking off or shifting, from worn gears, a loose yoke or backlash
• Leaks at the pinion seal, the carrier gasket or the axle seals
• Inter-axle differential trouble on tandems, including a power divider that will not lock or unlock
• Overheating after a low oil level or the wrong lube

How we handle it

We drain the oil and look at what comes out before anything else, because the metal in it says a lot about what is inside. From there the choice is the same as for a transmission: repair the failed parts, rebuild the carrier, or fit an exchange carrier and return the core. Exchange carriers come through pgttruckparts.com, which keeps the truck from sitting while a rebuild is on the bench.

Axles and makes

Single and tandem drive axles, front drive axles on 4x4 and 6x6 vocational trucks, and tag and pusher axles. The rear ends we work on include Eaton, Spicer, Meritor (Rockwell), Mack, Fabco and Marmon Herrington, under International, Freightliner, Kenworth, Peterbilt, Volvo, Mack, Western Star, Autocar, Crane Carrier, Oshkosh, Ford, GMC and Dodge trucks.