Collection
Where it applies, we arrange collection of your equipment or component at no charge.
24-Hour Rush Repair
Fontana, CA · Driveline bench
Differential Repair in Fontana
Wear inside a differential makes itself heard — a whine that rises and falls with speed, a clunk when direction changes, or metal clinging to the drain magnet. Our Fontana shop rebuilds differentials for trucks and equipment — ring and pinion setup, bearings, carriers and housings — bringing the gear expertise to set them up correctly and the machine shop to rescue units other shops would scrap.
Fontana, CA · Driveline bench
The setup is what makes the repair
Whether a differential lives or dies comes down to its setup: pinion depth, backlash, bearing preload and the tooth contact pattern. Our rebuilds verify those numbers rather than approximating them — which is why a differential rebuilt by a gear shop runs quietly and lasts. Gears that are damaged get replaced; gears that are obsolete get manufactured in-house.
Makes we work onDana SpicerMeritorEatonAAMFordCaterpillarKomatsuJohn Deere
Differential Repair in Fontana · Fontana, CAThe details of our differential service
We cover trucks from pickups through semis, plus differentials and axle drives on equipment. Regular hours run Monday–Friday 6 AM–5 PM, the rush line answers around the clock, and pick-up, delivery and quotes are free.
- Ring and pinion replacement with proper setup
- Renewal of bearings and carriers
- Repairs to axle housings
- Servicing for lockers and limited-slip units
- Manufacturing gears that are obsolete
How a repair moves through our shop — eight steps
From your first phone call through final testing, this is the route every job follows before it goes back into service.
Inspection
We take the unit apart and assess the full extent of the failure.
Photo & video record
Condition and findings get recorded, so the repair conversation stays clear and honest.
Written quote
The work we recommend gets defined and priced before anything proceeds.
Your approval
Scope, urgency and the sensible way forward get confirmed with you.
Making & rebuilding
Components get machined, welded, rebuilt or reverse-engineered as the job requires.
Testing
Operation and workmanship are verified before anything is released.
Return
The finished component or machine goes back into service with you.
Questions customers ask us
What is making my differential whine?
A whine that follows road speed usually points to worn gear teeth or a bearing on its way out — either way it only gets worse, and having us inspect it costs nothing.
Will you rebuild differentials from older trucks?
Yes — including manufacturing replacement gears for older and less common axles when the originals are no longer available.
More services from our shop
Truck down right now? Reach the around-the-clock rush line.
(949) 400-2937Book a service visit or start a repair order
Ask for a service visit.
Tell us the make and model, what the truck is doing, where it sits, how urgent it is, and when you would like us there. The form opens everything as a text message to John, so you can check it over before you hit send.