JLG T350 Service Manual - Manual (Page 40)

SECTION 3 - CHASSIS & TURNTABLE
3-4 – JLG Lift – 3121198
3. With a screwdriver or standard adjusting tool, rotate
the starwheel of the adjuster assembly to expand
the brake shoes. Adjust the brake shoes out until the
pressure of the linings against the drum makes the
wheel very difficult to turn.
4. Rotate the starwheel in the opposite direction until
the wheel turns freely with a slight lining drag.
5. Replace the adjusting hole cove and lower the wheel
to the ground.
6. Repeat the above procedure on all brakes. For best
results, the brakes should all be set at the same
clearance.
3.5 HUBS, DRUMS, WHEEL BEARINGS
The wheel bearing configuration consists of opposed
tapered roller bearing cones and cups, fitted inside of a
precision machined cast hub. This configuration requires
a minimal amount of end play be provided at assembly,
which is essential to the longevity of the bearing service
life. This design is lubricated with grease packed into the
bearings.
Hub Removal
1. Elevate and support the machine.
FOLLOW MAINTENANCE PROCEDURES TO PREVENT DAMAGE TO
IMPORTANT STRUCTURAL COMPONENTS. DAMAGE TO CERTAIN
STRUCTURAL COMPONENTS SUCH AS WHEEL BEARINGS CAN
CAUSE THE WHEEL END TO COME OFF OF THE AXLE. LOSS OF A
WHEEL END WHILE THE MACHINE IS MOVING CAN CAUSE A
LOSS OF CONTROL AND LEAD TO AN ACCIDENT, WHICH CAN
RESULT IN SERIOUS INJURY OR DEATH.
2. Remove the wheel.
3. Remove the grease cap by carefully prying progres-
sively around the flange of the cap.
4. Remove the cotter pin from the spindle nut.
5. Unscrew the spindle nut (counterclockwise) and
remove the spindle washer.
6. Remove the hub from the spindle, being careful not
to allow the outer bearing cone to fall out. The inner
bearing cone will be retained by the seal.
Brake Drum Inspection
1. The drum surface (where the brake shoes make
contact) should be inspected for excessive wear or
heavy scoring. If worn more than 0.020 in. (0.50
mm) oversized, or the drum has worn out of round
by more than 0.015 in. (0.38 mm), then the drum
surface should be re-machined. If scoring or other
wear is greater than 0.090 in. (2.28 mm) on the
diameter, the drum must be replaced (i.e. for a 10 in
[25.400 cm] drum, no greater than 10.090 in.[25.628
cm]).
NOTE: It is important to protect the wheel bearing bores
from metallic chips and contamination which result
from drum turning. Ensure the wheel bearing cavities
are clean and free of contamination before reinstall-
ing the bearing and seals. The presence of these
contaminants will cause premature wheel bearing
failure.
Bearing Inspection
Wash all grease and oil from the bearing cone using a
suitable solvent. Dry the bearing with a clean, lint-free
cloth and inspect each roller assembly.
NEVER SPIN THE BEARING WITH COMPRESSED AIR. THIS CAN
DAMAGE THE BEARING.
If any pitting, spalling, or corrosion is present, then the
bearing must be inspected.
BEARINGS MUST ALWAYS BE REPLACED IN SETS OF A CONE
AND CUP.
BE SURE TO WEAR SAFETY GLASSES WHEN REMOVING OR
INSTALLING FORCE FITTED PARTS. FAILURE TO COMPLY MAY
RESULT IN SERIOUS EYE INJURY.
When replacing the bearing cup proceed as follows:
1. Place the hub on a flat work surface with the cup to
be replaced on the bottom side.
2. Using a brass drift punch, carefully tap around the
small diameter end of the cup to drive out.
3. After cleaning the hub bore area, replace the cup by
tapping in with the brass drift punch. Be sure the
cup is seated all the way up against the retaining
shoulder in the hub.