Operation CHARM: Car repair manuals for everyone.

General Description

The 7 5/8 inch ring gear rear axle uses a conventional ring and pinion gear set to transmit the force of the engine to the rear wheels. This gear set transfers driving force at a 90-degree angle from the propeller shaft to the axle shafts. The centerline of the pinion gear is below the centerline of the ring gear (hypoid drive).

All parts necessary to transmit power from the propeller shaft to the rear wheels are enclosed in a salisbury-type axle housing (a carrier casting with tubes pressed and welded into the carrier). This axle is designed for use with an open driveline and leaf springs.





The axle assembly is a semi-floating type in which the vehicle weight is carried on the axle housing. The axle shafts are supported at the wheel end of the shaft by a roller bearing that is pressed into the housing. The shafts are retained in the housing by retaining clips within the differential. The pinion gear is supported by two tapered roller bearings. The pinion depth is set by a shim pack located between the gear end of the pinion and the roller bearing that is pressed onto the pinion. The pinion bearing preload is set by crushing a collapsible spacer between the bearings in the axle housing.

The differential allows the wheels to turn at different rates of speed while the rear axle continues to transmit the driving force. This prevents tire scuffing when going around corners and prevents premature wear on internal axle parts.

The differential case is supported in the axle housing by two tapered roller bearings. The differential ring gear
is meshed with the pinion gear by using selective shims and spacers between the bearings and the axle housing. The ring gear is bolted onto the differential case with JO left-hand thread bolts. To move the ring gear shims are removed from one side and an equal number are added to the other side. These shims are also used to preload the bearings which are pressed onto the differential case. Two bearing caps are used to hold the differential into the rear axle housing.

The rear axle is sealed with a pinion seal, a seal at each axle shaft end, and by a gasket between the rear cover and the axle housing.

A removable steel cover at the rear of the axle housing permits rear axle service without removing the entire assembly from the vehicle. The carrier cover does not have a drain plug.