GMC 25870034 Rear Axle Assembly (3.73 Ratio)

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To remove and install components in the front differential for AWD systems, follow these steps: Remove the stabilizer bar link and, if applicable, the front shock absorber. Unbolt the right driveaxle from the axleshaft flange, supporting it properly. Support the differential carrier with a floor jack and a block of wood. Remove nuts attaching the axle shaft to its support bracket and the bolts securing the axle shaft flange to the differential carrier. Use a brass punch and hammer to separate the axle shaft from the differential case side gear. Remove the inner axle shaft assembly and axle shaft. Replace the inner seal and bearing with a special tool, then apply RTV sealant to the differential sealing surface and install the inner axle shaft housing assembly. Install the axle shaft to the support bracket and align the splines with the differential side gear. Tap the axle shaft with a mallet until the ring (clip) aligns with the groove in the differential case side gear. Install the axle shaft to the inner flange and tighten the bolts. Reinstall the stabilizer link, fill the differential with lubricant, install the differential carrier splash shield, and finally, install the wheel and lug nuts. Lower the vehicle, tighten the lug nuts, and check for proper operation.

Before installing the driveaxle, the splines on the stub shaft should be lubricated with multi-purpose grease.

For models with a locking differential, you should rotate the differential until the shaft touches the case for access to the C-locks.

Symptoms of worn or damaged CV joints include lubricant leaks, clicking noise in turns, clunk when accelerating after coasting, and vibration at highway speeds.

The vehicle has a hypoid, semi-floating type rear axle assembly.

After installing the rear axle assembly, the brakes should be bled, the wheels and lug nuts should be installed, and the vehicle should be lowered. Finally, the lug nuts should be tightened to the proper torque specification.

To remove and install components in the front differential for AWD systems, follow these steps: Remove the stabilizer bar link and, if applicable, the front shock absorber. Unbolt the right driveaxle from the axleshaft flange, supporting it properly. Support the differential carrier with a floor jack and a block of wood. Remove nuts attaching the axle shaft to its support bracket and the bolts securing the axle shaft flange to the differential carrier. Use a brass punch and hammer to separate the axle shaft from the differential case side gear. Remove the inner axle shaft assembly and axle shaft. Replace the inner seal and bearing with a special tool, then apply RTV sealant to the differential sealing surface and install the inner axle shaft housing assembly. Install the axle shaft to the support bracket and align the splines with the differential side gear. Tap the axle shaft with a mallet until the ring (clip) aligns with the groove in the differential case side gear. Install the axle shaft to the inner flange and tighten the bolts. Reinstall the stabilizer link, fill the differential with lubricant, install the differential carrier splash shield, and finally, install the wheel and lug nuts. Lower the vehicle, tighten the lug nuts, and check for proper operation.

Symptoms of worn or damaged CV joints include lubricant leaks, clicking noise in turns, clunk when accelerating after coasting, and vibration at highway speeds.

The next step is to drain the differential lubricant and remove the differential cover.

When diagnosing axle problems, it is important to check for other possible causes such as road or tire noise, and to isolate engine and transmission noises.

No, overhauling the differential requires special tools and is not cost-effective for a do-it-yourselfer.

For leaf spring models, the spring U-bolts should be disconnected, followed by removing the springplates. Then, the jack can be lowered under the differential to remove the rear axle assembly.

After installing the rear axle assembly, the brakes should be bled, the wheels and lug nuts should be installed, and the vehicle should be lowered. Finally, the lug nuts should be tightened to the proper torque specification.

If a boot is damaged, the CV joint can be disassembled and cleaned, but if any parts are damaged, the entire driveaxle assembly must be replaced as a unit.

To remove and install components in the front differential for 4WD systems, follow these steps:Remove the bolts securing the axle tube to the differential carrier and the nuts attaching the tube to its support bracket.

The driveaxle/hub nut (new) and the flange bolts should be tightened to the torque values specifications during installation.

Before removing a semi-floating axle shaft, you should loosen the rear wheel lug nuts and raise the vehicle on jackstands.

The driveaxle/hub nut (new) and the flange bolts should be tightened to the torque values specifications during installation.

The initial steps to remove and install components in the front differential of selectable 4WD systems are as follows: Loosen the wheel lug nuts. Raise the vehicle securely on jackstands. Remove the right front wheel. Remove the differential carrier splash shield if equipped. Drain the lubricant from the front differential. For 4WD systems, unbolt the right driveaxle from the axleshaft flange and support it out of the way. Remove the front axle shift motor and, if applicable, disconnect the front stabilizer link or remove the front shock absorber/coil spring assembly. On 2500/3500 models, remove the front axle bracket bolts and slide the bracket forward for additional clearance. Support the differential carrier with a floor jack and a block of wood.

In 4WD models, an extension axle shaft is used on the right side to make up the difference in distance between the differential and the right front wheel.

It is also important to check the driveaxle shafts for cracks, dents, and distortion.

The inner end of the driveaxle should be lowered and pulled out of the hub, carefully guiding the driveaxle out from under the vehicle.

To remove a full-floating axle shaft, you need to remove the bolts attaching the flange to the hub and withdraw the shaft from the housing.

After installing the rear axle assembly, the brakes should be bled, the wheels and lug nuts should be installed, and the vehicle should be lowered. Finally, the lug nuts should be tightened to the proper torque specification.