Q2. An integral carrier is constructed as part of the axle housing. (T/F)

Q3. Rear axle ratio is determined by comparing the number of teeth on the _______ ________ to the ______ ________ number of teeth on the .

Q4. Excess ring and pinion backlash can cause a "clunking" sound when an automatic transmission is placed in drive. True/False

Q5. ____________ ___________ __________ often require a lubricant that is compatible with friction clutches.

Q6. Ring and pinion preload is a common differential adjustment. (T/F)

DRIVE AXLES

Learning Objective: Identify the parts of the rear drive axle and front drive axle. List the function of the rear axle. Compare the different types of axles. Describe the procedures for replacing axle bearings and seals.

Axles are classified as either LIVE or DEAD. The live axle is used to transmit power. The dead axle only serves as a support for part of the vehicle while providing a mounting for the wheel assembly. Many commercial trucks and truck-tractors have dead axles on the front, whereas practically all passenger vehicles use independent front-wheel suspensions and have no front axles.

The shaft in a live axle assembly may or may not actually support part of the weight of a vehicle, but it does drive the wheels connected to it. A live axle is involved with steering when it is a front drive axle. Some live rear axles are also designed to steer. The rear axle of conventional passenger vehicles is a live axle, while in a four-wheel drive vehicle both front and rear axles are live. In some six-wheel vehicles, all three axles are live axles.

AXLE HOUSING

The axle housing may be of the one-piece or split (banjo) type construction. The former, known as the banjo type because of its appearance, is far more common (fig. 5-22). Notice that openings, both front and rear, are provided in the center housing. The front opening is closed by the differential carrier, while the rear is closed by a spherical cover plate.

Since the assembly must carry the weight of the vehicle, the axle housing in heavy trucks and tractors is a heavy cast unit. In light-duty trucks it may be a combination of cast and steel tube; in general, the center or differential and final drive case is a cast and machined unit, whereas the axle housings themselves may be welded or extruded steel tubing.

Items, such as brake backing plates, mounting flanges, spring mounting plates, and accessory units, may be riveted, welded, or cast into the axle housing. Inspection covers are often provided through which

Figure 5-22. - Axle assembly.