Rear axle – general information
The rear axle assembly consists of a straight, hollow housing enclosing a differential assembly and axleshafts. These assemblies support the vehicle’s sprung weight components through leaf springs attached between the axle housings and the vehicle’s frame rails.
There are two different rear axle assemblies: light-duty axles are a semi-floating design, in which the axle supports the weight of the vehicle on the axleshaft in addition to transmitting driving forces to the rear wheels.
Heavy-duty models use a full-floating axle. A full floating axleshaft doesn’t carry any of the vehicle’s weight; this is supported on the axle housing itself by roller bearings. Full-floating axles can be identified by the large hub projecting from the center of the wheel. The axle flange is secured by bolts on the end of the hub.
Due to the need for special tools and equipment, it is recommended that operations on these models be limited to those described in this Chapter. Where repair or overhaul is required, remove the axle assembly and take it to a rebuilder, or exchange it for a new or reconditioned unit. Always make sure that an axle unit is exchanged for one of identical type and gear ratio.