JLG 450A_AJ Series II Service Manual - Manual (Page 119)

SECTION 3 - CHASSIS & TURNTABLE
3121180 – JLG Lift – 3-69
Assembly
Refer to Figure 3-49., Swing Bearing Drive.
1. Press bearing cup (17) in cap (12).
2. Place bearing cup (33) in housing (4).
3. Put face seal (18) and O-ring (19) on hub of worm
gear (20).
4. Place worm gear (20) on press with face seal up and
press pinion (10) into worm gear. Place Nilos Ring
(16) on pinion so cup shape is up and press bearing
(34) on pinion tight to Nilos Ring.
5. Turn assembly over and place spacer (21) on pinion
against gear hub so hub of spacer faces up. Press
bearing (22) on pinion and tight to spacer and gear.
6. Place pinion gear assembly in housing. Place gear
cap (12) and shims (14) over gear/pinion assembly
to achieve a slight preload on pinion bearings.
Remove cap and shims and set shims aside. Install
a new cover plate (9) on cap with six screws (15)
and shims (13) equal or close to total thickness of
shims removed. Apply sealant (Permatex #2) to
both sides of each shim and tighten screws, taking
care not to twist screws off. Set assembly aside.
ROLLER BEARINGS (3 0,36) AND CUPS (32,35) MUST BE
INSTALLED WITH SMALL ENDS FACING OUT ON EACH SIDE OF
MACHINE OR EXCESSIVE PLAY WILL CAUSE BINDING AND DAM-
AGE TO EQUIPMENT.
7. Install bearing (36) with small end facing to outside
of machine on bore end of worm (34).
8. Install worm (29), hex end first, into housing (4).
IF COMPRESSED AIR OR ELECTRICALLY OPERATED IMPACT
WRENCH IS USED FOR TIGHTENING THE BEARING ATTACH-
MENT BOLTS, THE TORQUE SETTING ACCURACY OF THE TOOL
SHOULD BE CHECKED PRIOR TO USE.
9. Install bearing cup (35) into worm bore of housing.
10. Install motor adapter (33) and 1 shim (34) to bore
end of housing using Install bearing (30) with small
end facing to outside of machine on hex end of
worm (29). Place bearing cup (32) over bearing and
lightly tap cup into bore using a soft hammer.
11. Install worm cap (26) using shims (27) to achieve
0.000 to 0.001" end play. Use 3/4" bolts (25) and
sealant. Torque to 80 ft-lb (108.5 Nm).
12. Install pinion/gear assembly in housing so gear
teeth mesh with worm gear teeth.
13. Apply silicone sealant to housing surface where cap
assembly touch. This includes vertical surface.
14. Place gear cap assembly over pinion assembly and
install shims set aside in step 6.
15. Install eight 3/8" 12 point screws (11) and torque to
60 ft-lb (81 Nm).
16. Install 2 small screws (8).
17. Install seal (28) in worm cap (26) at hex end of worm.
18. Install motor (3) to adapter (33) with two 1/2" bolts (1),
washers (2), and sealant. Torque to 80 ft-lb (108.5 Nm).
19. Install turntable bearing (7) to housing (4) with two 5/16"
bolts (5) and washers (6).
20. Fill unit with SHC 007 grease. Grease top bearing
with Mobil SHC 460 grease.
Installation
Refer to Figure 3-48., Swing Bearing Installation.
1. Install bearing to rotation box with two capscrews,
with fill plug of bearing close to gear as bolt pattern
allows. Do not tighten capscrews.
2. Line up high spot (blue) of bearing with center tooth
of worm gear. Set backlash to 0.008 - 0.010 inch
(0.20 - 0.25 mm). Tighten capscrews as shown in
Figure 3-50., Swing Bearing Torque Sequence.
3. Apply Mobiltac 375 Open Gear Compound or equiv-
alent to bearing and worm gear teeth.
4. Grease bearing. Grease fitting is on inside wall of
inner race of bearing or on newer bearings remove
plugs on both sides of bearing. Reinstall plugs after
greasing.
NOTE: If Mobiltac 375 Open Gear Compound is not avail-
able, Multi-Purpose Grease (MPG) can be substi-
tuted, however service interval will be shorter.
5. Using suitable lift equipment and install bearing/
rotation box assembly to frame with soft spot (red)
90 degree relative to load axis. If reusing old bear-
ing, ensure scribed line of outer bearing race aligns
with scribed mark on frame.
SWING BEARING IS THE ONLY STRUCTURAL LINK BETWEEN
FRAME AND TURNTABLE. JLG INDUSTRIES RECOMMENDS ALL
REMOVED GRADE 8 BEARING NUTS AND BOLTS BE DISCARDED
AND REPLACED WITH NEW NUTS AND BOLTS. IT IS IMPERATIVE
THAT REPLACEMENT HARDWARE MEETS JLG SPECIFICATIONS.
USE OF GENUINE JLG HARDWARE IS HIGHLY RECOMMENDED.
6. Apply a light coating of Loctite 271 to new bearing
bolts and loosely install bolts and washers through
frame and outer bearing race.