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Rear Drive Axle/Differential - Ford 10.50-Inch Ring Gear






Rear Drive Axle and Differential

Identification Tag










Ford Axle Identification Tag Denoting Interchangeability Affected Internally

NOTICE: The metal axle identification tag is the official service identifier. Do not damage the tag. Always reinstall the tag after removing it for axle inspection or repair for correct identification of axle components in the future.










The axle identification tag identifies a particular axle design, a specific ratio and if it is a conventional or limited slip (Traction-Lok(R)) type. The plant code will not change as long as that particular axle assembly never undergoes an external design change. If an internal design change takes place during the production life of the axle and that internal change affects parts change interchangeability, a dash and numerical suffix is added to the plant code. This means that as an assembly, both axles are interchangeable; however, internally they are different. Therefore, each requires different internal parts at the time of repair.

The Ford 10.50-inch rear axle features the following:

- The hypoid ring gear and pinion consists of a 10.50-inch diameter ring gear and an overhung drive pinion

- The pinion is positioned by selected pinion shims and supported by 2 opposed tapered roller bearings

- Pinion bearing preload is adjusted by the pinion nut and a collapsible spacer

- The rear axle housing consists of a cast center section with 2 steel tubes

- A stamped steel rear cover on gasoline engine applications

- A cast aluminum rear cover on diesel engine applications

- Differential housing cover uses a silicone sealant as a gasket

- Differential case is a 1- or 2-piece design depending upon the application. The differential pinion shaft in the 1-piece differential case design (2 pinion) is retained with a threaded bolt. The 2-piece differential case 3-pinion spider is retained by the case halves which are bolted together
- Motorcraft(R) SAE 75W-140 Synthetic Rear Axle Lubricant XY-75W140-QL meeting Ford specification WSL-M2C192-A

The rear axle drive pinion receives its power from the engine through the transmission and driveshaft. The drive pinion rotates the differential case through engagement with the ring gear, which is bolted to the case outer flange.

Inside the 2-piece differential case, 3 differential pinion gears are mounted on a 3-post shaft. Inside the 1-piece differential case, 2 differential pinion gears are mounted on a straight shaft. These differential pinion gears are engaged with the differential side gears to which the axle shafts are splined. Therefore, as the differential case turns, it rotates the axle shafts and rear wheels. When it is necessary for one wheel and axle shaft to rotate faster than the other, the faster turning differential side gear causes the differential pinion gears to roll on the slower turning differential side gear to allow differential action between the 2 axle shafts.