Chapter 12 Driveline and Wheel Components 263
the wheel mounting holes. On some wheels, an extra
stamping is used to attach the wheel cover, Figure 12-33.
The flange holds the tire in place once it is installed and
inflated.
Steel rims are relatively light and reduce the amount
of unsprung weight. They are also durable and cheap to
manufacture. Some steel rims are chrome plated for
appearance, while others are painted and used with wheel
covers.
Modern vehicles are increasingly using rims made of
materials other than steel. These rims are usually called
custom rims. Common materials for custom rims are
aluminum, aluminum-magnesium alloys, and composites
of graphite and plastic. Figure 12-34 shows a typical
custom wheel.
Axle housing
O-ring
Snap ring
Bearing retainer
Rear axle shaft
Brake drum
Drum
retaining
screw
Axle flange
Rear brake
assembly
Leaf spring
Figure 12-31. The brake drum mounts to the solid axle flange, which is forged as an integral part of the axle. (Toyota)
Mounting holes
Rim
Drop center section
Tire
bead
area
Spider
(center section)
Figure 12-32. A steel drop-center wheel. The center section
may be welded or riveted to the rim. This particular wheel is
welded together. (Chrysler)
Stamped bracket
Lug nut
Wheel
cover
Lock
bolt
Figure 12-33. Cross-sectional view of a wheel and tire. When
the tire is inflated, the flanges hold the tire to the wheel. The
safety ridges help hold the tire on the wheel if the tire goes flat
while the vehicle is moving. (Chrysler)
Figure 12-34. This custom wheel is made of aluminum. (Nissan)