JLG 450A_AJ Series II Service Manual - Manual (Page 81)

SECTION 3 - CHASSIS & TURNTABLE
3121290 – JLG Lift – 3-41
5. Use suitable lift equipment and install bearing/rotation
box assembly to frame with soft spot (red) 90 degree rel-
ative to load axis. If reusing old bearing, align scribed
line of outer bearing race with scribed mark on frame.
SWING BEARING IS THE ONLY STRUCTURAL LINK BETWEEN FRAME AND
TURNTABLE. JLG INDUSTRIES RECOMMENDS ALL REMOVED GRADE 8 BEAR-
ING NUTS AND BOLTS BE DISCARDED AND REPLACED WITH NEW NUTS AND
BOLTS. IT IS IMPERATIVE THAT REPLACEMENT HARDWARE MEETS JLG SPECI-
FICATIONS. USE OF GENUINE JLG HARDWARE IS HIGHLY RECOMMENDED.
6. Apply a light coating of thread locking compound JLG
PN 0100019 to new bearing bolts. Loosely install bolts
and washers through frame and outer bearing race.
IF COMPRESSED AIR OR ELECTRICALLY OPERATED IMPACT WRENCH IS USED
TO TIGHTEN BEARING ATTACHMENT BOLTS, CHECK TORQUE SETTING ACCU-
RACY OF TOOL BEFORE USE.
7. Tighten bolts to initial torque of 130 ft-lb (176 Nm) follow-
ing torque sequence shown in Figure 3-34., Swing Bear-
ing (Dohi) Torque Sequence. Tighten to final torque of
190 ft-lb (257 Nm) following same sequence.
Figure 3-34. Swing Bearing (Dohi) Torque Sequence
Figure 3-35. Swing Bearing (Jing Wei) Torque Sequence
8. Remove lifting equipment from bearing.
9. Use suitable lift equipment to carefully position turnta-
ble assembly above machine frame.
10. Carefully lower turntable onto swing bearing. Align
scribed line of inner race of bearing with scribed mark
on turntable. If a new swing bearing is used, align 1/8"
NPT holes with notches in frame.
Figure 3-36. Swing Bearing Alignment
11. Apply light coating of JLG Thread Locking Compound PN
0100019 to new bearing bolts and install through turnta-
ble and inner race of bearing.
12. Tighten bolts to an initial torque of 130 ft-lb (176 Nm)
following torque sequence shown in Figure 3-34., Swing
Bearing (Dohi) Torque Sequence. Tighten to a final
torque of 190 ft-lb (257 Nm) following same sequence.
13. Remove lift equipment.
14. Route hydraulic lines through center of turntable and
frame. Connect as tagged prior to removal.
15. Activate hydraulic system following all safety precautions.
Check swing system for proper and safe operation.
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Install bearing 1/8 in. NPT holes
aligned with notches in frame.