Chevrolet 1980 Light Duty Truck Service Manual page 271

MAINTENANCE AND ADJUSTM ENTS
NOTICE: See NOTICE on page 1 of this section
regarding the fasteners referred to in the maintenance
and adjustment procedures below.
W HEEL BEARINGS-CHECK A D JU S TM E N T
Tapered roller bearings are used on all series
NOTICE:
vehicles and they have a slightly loose feel when
properly adjusted. A design feature of front wheel taper
roller bearings is that they must NEVER be pre-loaded.
Damage can result by the steady thrust on roller ends
which comes from preloading.
1. Raise vehicle and support at front lower control
arm.
2. Spin wheel to check for unusual noise or roughness.
3. If bearings are noisy, tight, or excessively loose, they
should be cleaned, inspected and relubricated prior to
adjustment. If it is necessary to inspect bearings, see "Wheel
Hubs, Bearings" under "Component Parts Replacement."
To check for tight or loose bearings, grip the tire at the
top and bottom and move the wheel assembly in and out
on the spindle. Measure movement of hub assembly. If
movement is less than .025 mm (.001") or greater than . 127
mm (.005"), adjust bearings per adjustment procedure.
A D JU S TM E N T OF W HEEL BEARINGS (FIG. 3C-
3)
1. Remove hub cap or wheel disc from wheel.
2. Remove dust cap from hub.
3. Remove cotter pin from spindle and spindle nut.
4. Tighten the spindle nut to 16.26 N*m (12 ft. lbs.)
while turning the wheel assembly forward by hand to fully
seat the bearings. This will remove any grease or burrs
which could cause excessive wheel bearing play later. See
Fig. 3C-3.
5. Back off the nut to the "just loose" position.
6. Hand tighten the spindle nut. Loosen spindle nut
until either hole in the spindle lines up with a slot in the
nut. (Not more than 1/2 flat).
7. Install new cotter pin. Bend the ends of the cotter
pin against nut, cut off extra length to ensure ends will not
interfere with the dust cap.
8. Measure the looseness in the hub assembly. There
will be from .025 mm (.001) to .127 mm (.005 inches) end
play when properly adjusted.
FRONT SUSPENSION
9. Install dust cap on hub.
10. Replace the wheel cover or hub cap.
11. Lower vehicle to floor.
12. Perform the same operation for each front wheel.
2. TIGHTEN THE NUT TO
12 FT. LBS. FULLY SEAT
BEARINGS- THIS
OVERCOMES AN Y BURRS
O N THREADS.
4. HAND " SNUG
THE NUT
WHEN THE BEARING IS PROPERLY
ADJUSTED THERE WILL BE FROM
.0 0 1 - 005 INCHES END-PLAY
(LOOSENESS).
Fig. 3C-3--Wheel Bearing Adjustment
3C-3
BACK OFF NUT
UNTIL JUST LOOSE
POSITION.
i. LOOSEN NUT UNTIL EITHER HOLE
IN THE SPINDLE LINES UP WITH
A SLOT IN THE NUT-THEN
INSERT COTTER PIN.
NOTE: BEND ENDS OF COTTER PIN
AG AINST NUT, CUT OFF EXTRA
LENGTH TO PREVENT
INTERFERENCE W ITH DUST CAP.
L IG H T T R U C K S ER V IC E M ANUAL