GM 22506477 Rear Axle Shaft

The usual reason for axleshaft removal on this type of axle is that the shaft end play has become excessive. To check this, remove the wheel and brake drum and attach a dial gauge with its stylus against the axleshaft end flange. If the shaft is then moved in and out by hand, the end play should not exceed 0.022 inch. If the end play is excessive, carry out the following operations as the shaft bearing is probably worn. Unscrew and remove the bolts which attach the axleshaft retainer plate to the brake backing plate. Attach a slide hammer to the wheel mounting studs and withdraw the axleshaft. Do not attempt to pull the axleshaft by hand from the housing as you will only succeed in pulling the vehicle off the support stands. As the axleshaft is removed, it is possible that the bearing will become separated into three parts. This does not indicate that the bearing is unserviceable. If this happens, remove the two sections left behind from the axle tube. With the axleshaft removed, hold it in the jaws of a vise so that the bearing retainer ring rests on the edges of the jaws. Using a hammer and a sharp chisel, nick the retainer in two places. This will have the effect of spreading the retainer so that it will slide off the shaft. Do not damage the shaft in the process and never attempt to cut the retainer away with a torch as the temper of the shaft will be ruined. Using a suitable press or extractor, withdraw the bearing from the axleshaft. Remove and discard the oil seal. When installing the new bearing, make sure that the retainer plate and the seal are installed to the shaft first. Press on the bearing and the retaining ring tight up against it. Before installing the axleshaft assembly, smear wheel bearing grease onto the bearing end and in the bearing recess in the axlehousing tube. Apply rear axle oil to the axleshaft splines. Hold the axleshaft horizontal and insert it into the axle housing. Feel when the shaft splines have picked up those in the differential side gears and then push the shaft fully into position, using a soft faced hammer on the end flange as necessary. Bolt the retainer plate to the brake backplate, install the brake drum and wheel and lower the vehicle to the ground.

Raise the rear of the vehicle and support it securely on stands placed under the body frame rails. Position an adjustable floor jack under the differential housing and just take up the weight. Do not raise sufficiently to take the weight of the vehicle from the frame stands. Disconnect the lower shock absorber mountings. Remove the driveshaft. Remove the rear wheels and brake drums. Disconnect the hydraulic brake lines from their clips on the axle housing. Unbolt and remove the differential cover, allowing the fluid to drain into a suitable container. Remove the axle shafts depending on type. Unbolt the brake backing plates, carefully withdraw the brake assemblies and wire them up to the frame without bending the hydraulic lines or disconnecting them. Remove the leaf springs. Withdraw the axle assembly from under the vehicle. Installation is a reversal of removal but tighten all suspension bolts and nuts to the specified torque. Fill the axle assembly with the proper grade and amount of lubricant.

The operations for rear axles with pressed wheel bearings are as follows, First, raise the rear of the vehicle and remove the wheel and brake drum. Then, remove the pressed steel cover from the differential carrier to drain the oil. Next, remove the lock screw and pinion shaft. After that, remove the C-ring from the inner end of the axleshaft. Carefully withdraw the axleshaft, being mindful of the oil seal. To reinstall, follow the reverse order of removal, ensuring the lock screw is tightened to the specified torque. Always use a new cover gasket and tighten the cover bolts to the specified torque. Finally, refill the unit with the correct lubricant.

The rear axle is of hypoid semi-floating type, with a casting differential carrier and a pressed steel cover. The axle tubes are made of steel construction. Due to the need for special gauges and equipment, as well as the unavailability of individual differential components, servicing and repair operations should be confined. An optional Positraction (limited slip) differential unit has been available since the earliest models, which includes clutch cones or plates and springs to slow down the rotation of the differential case when one wheel is on a firm surface and the other on a slippery one. The axle identification number, located on the front face of the right-hand axle tube, is important for certain operations such as the removal of the axleshafts. The axle code, which can be determined using the axle code and ratio chart, indicates the gear ratios installed in the axle assembly. The third letter of the code identifies the manufacturer of the axle, with slight variations in axle design between manufacturers. The numbers following the manufacturer's code indicate the day of the year the axle was built, with the letter D or N representing day or night shift. The last letter of the code identifies a locking axle (Positraction), with different code letters for different manufacturers. The axle code chart provides information on the gear ratio and year of each axle assembly, with later vehicles potentially having the axle ratio stamped on the housing.

The rear axle operations for axles with pressed wheel bearings involve raising the rear of the vehicle, removing the wheel and brake drum, unscrewing and removing the pressed steel cover from the differential carrier to drain the oil.

To remove the rear axle assembly, start by raising the rear of the vehicle and supporting it securely on stands placed under the body frame rails. Then, position an adjustable floor jack under the differential housing to take up the weight without raising it too high. Disconnect the lower shock absorber mountings and remove the driveshaft, rear wheels, and brake drums. Disconnect the hydraulic brake lines from their clips on the axle housing and remove the differential cover to drain the fluid. Depending on the axle type, remove the axle shaft and brake backing plates, carefully withdrawing the brake assemblies and wiring them up to the frame without bending the hydraulic pipes. Finally, remove the leaf springs and withdraw the axle assembly from under the vehicle. To install, simply reverse the removal steps and make sure to tighten all suspension bolts and nuts to the specified torque. Don't forget to fill the axle assembly with the proper grade and amount of lubricant.

The usual reason for axleshaft removal on this type of axle is excessive shaft end play. To check this, remove the road wheel and brake drum and attach a dial gauge to the axleshaft end flange. If the shaft can be moved in and out by hand, the end play should not exceed 0.022 inches. If it does, the shaft bearing is likely worn and the following operations should be carried out. First, unscrew and remove the bolts attaching the axleshaft retainer plate to the brake backing plate. Then, attach a slide hammer to the road wheel mounting studs and withdraw the axleshaft, avoiding pulling it by hand from the housing. As the axleshaft is removed, the bearing may separate into three parts, but this does not mean it is unserviceable. If this happens, remove the two sections left behind from the axle tube. With the axleshaft removed, hold it in a vise so that the bearing retainer ring rests on the jaws' edges. Use a hammer and sharp chisel to nick the retainer in two places, spreading it to slide off the shaft without damaging it. Do not attempt to cut the retainer with a torch as it will ruin the shaft's temper. Use a press or extractor to withdraw the bearing from the axleshaft and remove and discard the oil seal. When installing the new bearing, ensure the retainer plate and seal are installed to the shaft first, pressing the bearing and retaining ring tightly against it. Before installing the axleshaft assembly, apply wheel bearing grease to the bearing end and races in the axle housing tube, and rear axle oil to the axleshaft splines. Hold the axleshaft horizontally and insert it into the axle housing, feeling when the shaft splines engage with those in the differential side gears, and then push the shaft fully into position using a soft-faced hammer on the end flange if necessary. Finally, bolt the retainer plate to the brake backplate, install the brake drum and wheel, and lower the vehicle to the ground.