Rebuilt Differential

How To Identify Your Differential

There are two ways to determine your differential. The first way is to use the axle numbers. This can come either in the form of an axle tag which is bolted onto the axle with the differential bolts, or with an axle stamp pressed into the differential cover itself. If your  ID tag can’t be read you can identify your differential by looking at the cover and finding the number of cover bolts, the distinctive shape of the cover, the number of ring gear bolts, and ring gear diameter. They can also be identified by whether the center section is an integral or dropout design. Dropout differentials are also referred to as 3rd members or pumpkins. If you are having trouble identifying your differential, give us a call and we are happy to help, 877-776-4600 or 407-872-1901.

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How do I know what my gear ratio is?

Your axle gear ratio determines how many times your driveshaft rotates for every full tire rotation. The gear ratio can often be determined from the vehicle’s VIN code or listed on the axle tag. Some manufacturers, may not include that information in the VIN. The ratio can also be found by dividing the number of teeth on the ring gear by the number of teeth on the pinion gear.

[ Ring Gear Teeth / Pinion Gear Teeth ] = [ 41 / 11 ] = [ 3.73 ]


Calculate your gear ratio below by entering the number of teeth on your ring gear & pinion gear.

ring & pinion gears

Gear Changing Tips

Larger tires aren’t the only reason you may need to change gears:

  • Many truck owners swap gears for better mileage.
  • If your vehicle is a 4×4, you will need to change the gears in both front and rear axles.
  • Most front axles require reverse cut gears because front driveshafts typically spin the other way.
  • Front and rear gears can be different by 1% on road and 2% off-road without impacting performance.

If you have any questions or need assistance, give us a call.

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Select your make below:

rebuilt Rockwell Differential
Mack Differential
Marmon Herrington Differential
Spicer Differential
Fabco Differential
International Differential
Meritor Differential
Oshkosh Differential
Eaton Differential

Differentials, Ring and Pinion, Crown Wheel and Pinion, new, used, rebuilt and exchange. One call does it all. We have all models in stock ready to ship worldwide today. One call to us and we can provide international shipping.

Our experienced staff can help you find the Differentials you are looking for. If you don’t see the Differentials you need on our website, please call us at 877-776-4600, we will be glad to assist you