Chevrolet 70 1969 Series, Руководство по ремонту

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FRONT SUSPENSION 3D-17
SECTION 3D
FRONT HUBS AND BEARINGS
DESCRIPTION
Front hubs are mounted to steering knuckle
spindles on opposed tapered roller bearings as
illustrated in figures 1 and 2. Mounting parts,
mainly bearings, spindle nuts and seals shown are
of primary importance. Brake drum mounting bolts,
studs and nuts, differ in type and method of in­
stallation on various series vehicles.
BEARING MAINTENANCE
All wheel bearings are adjustable for wear.
Satisfactory operation and long life of bearings,
depend upon proper adjustment and correct lubri­
cation. If bearings are adjusted too tight, they will
overheat and wear rapidly. Loose adjustment will
cause pounding and will also contribute to steering
difficulties, uneven tire wear, and inefficient brakes.
Bearing adjustment should be checked at regular
inspection periods.
Hubs and bearings should be cleaned, inspect­
ed, and lubricated whenever hubs are removed, or
at intervals indicated in LU B R IC A T IO N (SEC. 0)
of this manual.
New hub oil seals should be installed when
servicing bearings if there is the slightest indi­
cation of leakage, wear, or damage. An imperfect
seal may permit bearing lubricant to reach brake
linings, resulting in faulty brake operation and
necessitating premature replacement of linings.
BEARING ADJUSTMENT
Before checking wheel bearing adjustment,
make sure brakes are fully released. Jack up the
front axle until tires clear floor.
Check bearing play by grasping tire at top and
pulling back and forth, or by using a pry bar under
tire. If bearings are properly adjusted, movement
of brake drum in relation to backing plate will be
barely noticeable and wheel will turn freely. If
movement is excessive, adjust as follows:
FRONT WHEEL BEARING
ADJUSTMENT
1. With the wheel raised and axle safely sup­
ported, remove hub cap, or hub closure plate and
gasket.
2. Remove cotter pin securing adjusting nut
to spindle.
3. Back off the adjusting nut slightly, then us­
ing a torque wrench, retighten adjusting nut to 50
foot-pounds torque, at the same time turn wheel in
both directions until there is a slight bind, to be
sure all bearing surfaces are in contact.
4. Back off adjusting nut 1/6 to 1/4 turn, or to
the nearest cotter pin hole in spindle, or suffic­
iently to allow the wheel to rotate freely within
limits of 0.001” to 0.007" end play.
5. Install new cotter pin. Make sure that wheel
or hub turns freely.
6. Install hub cap or hub closure plate with
new gasket, and tighten cap screws firmly.
7. Lower wheel to floor and remove jack.
FRONT HUB AND BEARING
REPLACEMENT
R E M O V A L (Figs. 1 and 2)
1. Jack up front wheel and remove tire and
rim assembly if cast wheels are used. Remove
tire and wheel assembly if ventilated disc wheels
are used.
2. Remove hub cap or hub closure plate and
gasket.
3. Remove cotter pin, bearing adjusting nut,
and adjusting nut washer.
4. Pull hub and drum assembly straight off
steering knuckle spindle, using care to prevent
outer bearing cone and roller assembly from drop­
ping on floor. Remove outer bearing cone and roll­
er assembly from hub.
5. Pull inner oil seal out of hub; then remove
inner bearing cone and roller assembly from hub.
Discard oil seal.
6. Clean, inspect, and repair parts as neces­
sary as directed later in this section under "Clean­
ing, Inspection, and Repair."
IN S T A L L A T IO N (Figs. 1 and 2)
1. After completing "Cleaning, Inspection, and
Repair" operations described later in this section,
lubricate bearings, spindle, and inside of hub as
described in LU B R IC A T IO N (SEC. 0) of this manual.
2. On vehicles using felt-type oil seal, soak
seal in clean oil before installing. On all other
type oil seals, coat lip of seal with wheel bearing
grease or equivalent before installing.
3. Place inner bearing cone and roller assem­
bly in hub.
4. Coat oil seal bore in hub with a thin layer
of non-hardening sealing compound; then press
new oil seal in hub, until seal case seats against
CHEVROLET SERIES 70-60 H EAVY DUTY TRUCK SH O P M A N U A L