6 3/4 Inch Ring Gear Axle

��n;Fig. 1 Disassembled view of Ford 6 3/4 inch ring gear axle:

DESCRIPTION

This axle can be identified by the 8 cover bolts.The axle, Fig. 1, is an integral design hypoid with the center line of the pinion set below the center line of the ring gear. The semi-floating axle shafts are retained in the housing by ball bearings and bearing retainers at axle ends.

The differential is mounted on two opposed tapered roller bearings which are retained in the housing by removable caps. Differential bearing preload and drive gear backlash is adjusted by nuts located behind each differential bearing cup.

The drive pinion assembly is mounted on two opposed tapered roller bearings. Pinion bearing preload is adjusted by a collapsible spacer on the pinion shaft. Pinion and ring gear tooth contact is adjusted by shims between the rear bearing cone and pinion gear.

REAR AXLE ASSEMBLY, REPLACE
1. Raise vehicle and support at rear frame members.
2. Drain lubricant from axle.
3. Mark driveshaft and pinion flange for proper reassembly. Disconnect driveshaft from pinion flange.
4. Remove wheels, brake drums and both axle shafts as outlined in ``Axle Shaft & Oil Seal, Replace.''
5. Remove vent tube hose, then remove vent tube from axle housing.
6. Remove bolt securing hydraulic brake T-fitting from axle housing, then carefully remove the hydraulic brake hose from retaining clip. Carefully wire rear brake backing plates, hydraulic brake system and parking brake cables as one unit out of the way.
7. Using a suitable jack, support rear axle. Remove U-bolts, shock absorber lower mounting and spring plates.
8. Lower axle housing and remove from vehicle.
9. Reverse procedure to install, noting the following torques: U-bolt nuts, 55-75 ft. lbs., shock absorber lower mounts, 40-60 ft. lbs., driveshaft to pinion flange bolts, 70-95 ft. lbs., rear axle shaft retainer plate nuts, 20-40 ft. lbs. and rear cover attaching bolts, 23-35 ft. lbs., except the ratio tag bolt which is torqued to 15-20 ft. lbs.

AXLE SHAFT & OIL SEAL, REPLACE
1. Remove wheel and tire assembly, then remove nuts attaching brake drum to axle shaft flange and remove brake drum.
2. Working through opening in axle shaft flange, remove nuts securing axle shaft bearing retainer.
3. Using a suitable puller, pull axle shaft from housing.
4. Remove brake backing plate and attach to frame side rail with a piece of wire.
5. Using a hook type puller, remove oil seal from housing.
6. Wipe all lubricant from oil seal area of axle housing, then install oil seal using tool No. T79P-1177-A.
7. Install gasket on housing flange, then install brake backing plate.
8. Carefully slide axle shaft into housing using care not to damage oil seal, then install bearing retainer attaching nuts and torque to 20 to 40 ft. lbs.
9. Install brake drum and retaining nuts, then install wheel and tire assembly.

AXLE SHAFT BEARINGS, REPLACE
1. Remove axle shaft as described in ``Axle Shaft & Oil Seal, Replace.''
2. Loosen axle inner retainer ring by nicking deeply with a cold chisel in several places and slide off shaft.
3. Using a suitable press, remove bearing from axle. Do not ever attempt to use heat to make bearing removal easier, as it will weaken the axle shaft bearing journal area.
4. Position bearing retainer plate and bearing on axle, then using a suitable press, install bearing. Using the same tool, install bearing retainer ring. Do not press on the bearing and the retainer ring at the same time. They must be installed separately.
5. Reinstall axle in axle housing. Ensure new seal is installed.