JLG 450A_AJ Series II Service Manual - Manual (Page 80)

SECTION 3 - CHASSIS & TURNTABLE
3-30 – JLG Lift – 3121180
3.3 TORQUE HUB (MACHINES BUILT AFTER
S/N 0300071527)
Roll and Leak Testing
Always roll and leak test Torque-Hubs after assembly to
make sure that the unit’s gears and sealants are working
properly. The following information briefly outlines what to
look for when performing these tests.
ROLL TEST
The purpose of a roll test is to determine if the unit’s gears
are rotating freely and properly. You should be able to
rotate gears by applying a constant force to the roll
checker. If you feel more drag in the gears only at certain
points, gears are not rolling freely and you should exam-
ine them for improper installation or defects. Some gear
packages roll with more difficulty than others. Do not be
concerned if gears seem to roll hard as long as they roll
with consistency.
LEAK TEST
The purpose of a leak test is to make sure unit is air tight.
You can tell if your unit has a leak if pressure gauge test
reading starts to fall once you have pressurized the unit.
Leaks usually occur at the main seal or wherever O-rings
or gaskets are located. Usually, you can detect the exact
location of a leak by brushing a soap and water solution
around the main seal and where O-rings or gaskets meet
unit exterior, then checking for air bubbles. If you detect a
leak in a seal, O-ring, or gasket, replace part immediately.
Tightening and Torquing Bolts
USE EXTREME CARE WHEN USING AN AIR IMPACT WRENCH. DO
NOT TIGHTEN BOLTS BEYOND THEIR TORQUE SPECIFICATION.
NEVER USE AN IMPACT WRENCH TO TIGHTEN SHOULDER
BOLTS. ALWAYS TIGHTEN A11 SHOULDER BOLTS BY HAND.
The following steps describe proper procedure for tighten-
ing and torquing bolts or socket head capscrews in a bolt
circle.
1. Tighten (but do not torque) bolt ”A” until snug.
2. Go to opposite side of bolt circle and tighten bolt ”B”
until equally snug.
3. Continue around bolt circle and tighten remaining
bolts.
4. Use a torque wrench to apply specified torque to
bolt ”A”.
5. Continue around bolt circle and apply equal torque
to remaining bolts.
Oil Information
1. 1. TYPE – EP90
Use EP90 for normal applications. For applications
where lubricant must meet special requirements, the
O.E.M can recommend a suitable substitute.
2. OIL TEMPERATURE
Continuous – 160° F (70° C) Intermittent – 200° F
(95° C).
3. OIL CHANGE
Initial – After 50 hours or 50,000 revolutions of oper-
ation. Subsequent – After 1000 hours or (1) year,
whichever comes first.
NOTE: Higher temperatures make it necessary to change oil
more frequently.
4. OIL FILL LEVEL AND VOLUME
Unit mounted horizontal – half full. (See Diagram A.)
Approximate volume - 17 oz. (0.5 1tr).
MAIN DISASSEMBLY for “B” Drives
1. Turn hub (1G) on side, Remove coupling (14) from
wide end of spindle (1A).
2. Mark location of shoulder bolt holes on outside of
ring gear and hub for easy realignment when
rebuilding. Remove four shoulder bolts (13) and 12
bolts (12) from cover (6).
3. Remove 16 flat washers (16) from cover (6).
4. Lift cover sub-assembly (6) off ring gear (4). Set
cover on table with interior side facing up.
SHARP EDGES CAN CUT AND CAUSE SERIOUS INJURY. BEWARE
OF SHARP EDGES IN COUNTERBORE WHEN REMOVING O-RING.
5. Remove O-ring (5) from counterbore around edge of
cover (6A). Discard O-ring.
NOTE: If O-ring is not in cover counter- bore, it is in ring
gear counterbore. Remove it from hub and discard.
6. Remove thrust washer (11) from counter- bore in top
of carrier (3A).
7. Remove input gear (8) from middle of carrier sub-
assembly (3).
8. Lift ring gear (4) off hub (1G).
9. Lift carrier sub-assembly (3) out of hub (1G).
10. Remove thrust spacer (9) from input shaft (7) in mid-
dle of spindle (1A).
11. Lift input shaft sub-assembly (7) out of middle of
spindle (1A). Stand input shaft (7A) on splined end.