256 Auto Suspension and Steering
In operation, the cross of the U-joint transmits power
between the two yokes. Since the cross cannot move back
and forth, the drive angle changes as the shaft rotates
through an angle. This causes the speed of the driven part
of the drive shaft to vary. See Figure 12-17. The greater the
angle, the more the vibration. For this reason, U-joints are
used only where the angle between the yokes is relatively
small.
Due to their design, cross-and-roller U-joints do not
require a surrounding boot. Seals at the ends of the bearing
caps (where they enter the cross) keep lubricant in and
water and dirt out. Many U-joints are equipped with grease
fittings. Conventional front suspension lubricant can be
used to lubricate U-joints.
Wheel Components
The following sections cover the components related
to a vehicle’s wheels. These components, which include
the wheel hubs, bearings, rims, tires, and fasteners, are
found on both driving and non-driving axles.
Propeller
shaft and
center bearing
Washer (2)
Bolt (2)
68 N•m
(50 ft. lbs.)
Clamp
Rear propeller
shaft
Slip
yoke
Clamp
Boot
Propeller
shaft
Rear axle assembly
Screw and
washer assembly
Clamp
Propeller shaft
Slip yoke
Output
shaft
Transmission
Figure 12-9. A two-piece drive shaft showing the slip yoke. (Chrysler)
Wheel
Brake rotor
Hub
Ball bearing
Ball joint
Constant velocity
joint
Boot
Damper
Support
bearing
Differential
Intermediate
shaft
Constant velocity
joint
Strut
Drive
shaft
Figure 12-10. Cutaway of both inboard and outboard CV joints.
(Honda)
Balls (6)
Inner race
Cage
Outer race
Elongated
opening
Figure 12-11. Exploded view of a Rzeppa (ball-type) constant
velocity joint. (AC Delco)