Originally Posted By: supton
How are they lubricated? Is the oil level high enough that they sit in oil? I don't think there is a splash lube going on--or does the ring spray enough all around that it gets over there?
Was reading a Hot Rod article; they pulled axles in a Pontiac, which was said to be easy because no C clips meant no need to drain the lube. Which makes me think they are weakly splash lubed.
It depends on the axle design. For example, the Chrysler 8-3/4 axle from the old days (a Hotchkiss axle wherein the gear assembly comes out of the front of the axle housing similar to a Ford 9", identifiable by a hemispherical back surface and no cover plate) has grease-packed wheel bearings that are sealed off from the gear lube and packed with regular wheel bearing grease. The axles are retained in the housing by adjuster disks which set the bearing clearances. re-packing the bearings requires at least partially sliding the axle out of the housing since the tapered-roller bearings are pressed onto the axle.
On the other hand, the Chrysler 8-1/4 (a Salisbury axle with a removable back plate where the gears have to be serviced in the complete axle) has C-clip retained axles and straight roller bearings which ride directly on the axle surface, and are lubricated by the rear end gear lube. There's a single seal that keeps the oil in the housing and the dirt, water, and air out.
Both of the above types are common among most manufacturers. Heavy trucks often have "full floating" axles where the axle can be slid out of the truck with the wheel still sitting on the ground via a center access plate, and the bearings are completely external to the axle assembly itself. The axle drives the hub via splines. Those are (obviously) not lubricated by the rear axle lube, but may have their own gear lube reservoir or be lubricated by grease.
