Description

The Ford Truck Integral Carrier rear axle assembly is an integral type housing, hypoid gear design with the centerline of the pinion set below the centerline of the ring gear.

The hypoid gear set consists of an 10-1/4 inch diameter ring gear and an overhung drive pinion which is supported by two opposed tapered roller bearings. Pinion bearing preload is adjusted by the pinion nut and a collapsible spacer maintains the seating of the inner race.

The housing assembly consists of a cast center section with two steel tube assemblies and a stamped rear cover. The cover uses a silicone sealant as a gasket.

The differential case is a one-piece design with two openings to allow for assembly of the internal components and lubricant flow. The differential pinion shaft is retained with a threaded bolt assembled to the case. The differential case assembly is mounted in the carrier between two opposed tapered roller bearings. The bearings are retained in the carrier by removable bearing caps.

The full-floating rear axle features brake drums that are mounted outboard of the hub. Therefore, when brake inspection or replacement is required the hub assembly need not be removed.

The hub is supported or "floats" on the axle spindle on two opposed tapered roller bearings. It is retained on the spindle by a ratcheting nut that is tabbed to a slot on the spindle. If, for any reason, the hub is removed from the spindle, the old hub seal must be removed and a new hub seal installed.

Functional differences between the semi-float integral rear axle assembly and the full4loat integral rear axle assembly are as follows:

1. The semifloat axle shafts are retained in the axle by C-washer locks positioned in a slot on the axle shaft splined end. These C-washers also fit into a machined recess in the differential side gears within the differential case.

2. The full-float axle shafts are retained by bolts attached to the hub. The hub rides on two bearings at the outboard end of the axle tube.

3. A semifloat axle shaft rides on one straight- roller bearing at the outboard end.

- Differential Bearing Preload and Ring Gear Backlash are adjusted by the use of shims located between the differential bearing cupi races and the carrier housing.

- The use of a Pinion Depth Gauge Tool for drive pinion shim selection in conjunction with a dial indicator for differential case shim selection is required for proper gear set adjustment.

Rear Antilock Brakes

F-250/F-350 vehicles use the Rear Antilock Braking System. The system is designed to automatically reduce brake pressure when brake lock-up is detected during braking or on slippery surfaces. The system features a multi-tooth excitor ring that is pressed on the differential case behind the ring gear. If the excitor ring is removed, it must be discarded and replaced with a new one. The excitor ring works in conjunction with an electronic speed sensor. This sensor is retained in a bore at the top of the carrier housing and fastened by one bolt. There is a space provided between the ring gear and excitor ring for measuring the ring gear backface runout.