260 Auto Suspension and Steering
Tapered roller bearing preload is always adjustable.
An adjusting nut, or hub nut, on the threaded spindle
is tightened to set preload, Figure 12-25. After the preload
is set, the nut is held in position by a cotter pin,
Figure 12-26, or by staking (bending) the outer part of the
nut into a slot on the spindle, Figure 12-27.
Wheel Bearing Lubrication
Although wheel bearings operate with a minimum of
resistance, they develop some friction. Bearing lubricant
must maintain a film of lubricant between the rotating and
stationary elements of the bearing to reduce friction and
wear. It must also coat the surfaces of the bearing to
prevent corrosion.
Lubrication Methods
Wheel bearings are lubricated in one of several ways.
Most tapered wheel bearings are packed (filled) with
wheel bearing grease. These bearings must be periodically
removed, cleaned, and repacked with the proper grease.
Strut
Disc brake caliper
Axial
load
Ball joint
Brake rotor
Double row
ball bearings
Axial
load
Hub
Figure 12-22. This dual ball bearing assembly will handle thrust
(axial) loads in opposite directions. (Toyota)
Oil
seal
Axle flange
Backing
plate
Outer
bearing
race
Lug
bolt
Straight roller
bearing
Axle housing
Axle
shaft
Figure 12-23. Cutaway view of a rear axle illustrating straight
roller bearings. (General Motors)
Oil
seal
Inner tapered
roller bearing
Outer tapered
roller bearing
Hub and disc
Thrust
washer
Nut lock
Cap
Cotter
pin
Nut
Figure 12-24. This application uses tapered roller bearings.
(Toyota)
Lug bolt
Washer
Hub
nut
Stub axle or spindle
Bearing
Cotter pin
hole
Hub and
bearing
Figure 12-25. A hub nut is used for setting bearing preload.
(Chrysler)