GM 26050549 Rear Axle Drive Shaft

The rear axle assembly is a hypoid, semi-floating type with a differential that allows the outer rear tire to turn more quickly than the inner tire when the vehicle goes around a corner. The axle shafts are splined to the differential side gears, causing the inner tire to turn more slowly than the outer tire. The differential pinion gears roll around the slower side gear, driving the outer side gear and tire more quickly. The differential is housed within a casting with a pressed steel cover known as the "carrier," and the steel axle tubes are pressed into and welded to the carrier. On 4WD models, a fully independent front axle assembly is used, consisting of a differential and a pair of driveaxles with inner and outer constant velocity (CV) joints. An extension axleshaft is employed on the right side to make up the difference in distance between the differential and the right front wheel. An optional locking limited-slip rear axle is also available, which allows for normal operation until one wheel loses traction. This differential includes a pair of clutch "cones" that slow the rotation of the differential case when one wheel is on a firm surface and the other on a slippery one, equalizing the rotation speed of the axleshaft driving the wheel with traction. It is important to check for other possible causes before assuming the axle is the problem, as road noise, tire noise, and engine and transmission noise can be mistaken for axle issues. Overhauling the differential may require special tools and is not typically cost-effective for a do-it-yourselfer.