GM Service Manual Online
For 1990-2009 cars only

Rear Axles for this vehicle consist of the following components:

    • Differential Axle Housing
    • Differential Carrier
    • Electronic Locking Mechanism
    • Right and left Axle tubes
    • Right and left axle shafts

The H2 uses the 9.50 inch ring gear axle. This type of the axle can be identified by the stamping on the right side axle tube. It may also be identified by the ring gear size. The locking differential information for this rear axle can be located in the locking differential section.

This differential has a set of 4 gears. 2 are side gears and 2 are pinion gears. Each side gear is splined to an axle shaft so each axle shaft turns when its side gear rotates. The pinion gears are mounted on a differential pinion shaft, and the gears are free to rotate on this shaft. The pinion shaft is fitted into a bore in the differential case and is at right angles to the axle shafts. Power is transmitted through the differential as follows: The drive pinion rotates the ring gear which is bolted to the differential case assembly. The differential pinion, as it rotates with the case, forces the pinion gears against the side gears. When both wheels have equal traction, the pinion gears do not rotate on the pinion shaft because the input force on the pinion gear is equally divided between the 2 side gears. Therefore the pinion gears revolve with the pinion shaft; but do not rotate around the shaft itself. The side gears; being splined to the axle shafts, and in mesh with the pinion gears rotate the axle shafts. When the vehicle turns a corner the inner wheel turns slower than the outer wheel which slows the rear axles' side gear. The rear axle pinion gears will roll around the slower moving rear axle side gear; driving the rear axle side gear wheel faster.