JLG 450AJ Service Manual - Manual (Page 42)

SECTION 2 - PROCEDURES
2-26 – JLG Lift – 3120869
3. Apply Mobiltac 375NC Open Gear Compound to
bearing and worm gear teeth.
4. Grease bearing with Mobilith SHC Bearing Grease.
Grease fitting is on inside wall of inner race of bear-
ing.
NOTE: If Mobiltac 375NC Open Gear Compound or Mobilith
SHC Bearing Grease are not available, Multi-Pur-
pose Grease (MPG) can be substituted, however the
service interval will be shorter.
5. Using suitable lifting equipment, install bearing/rota-
tion box assembly to frame with soft spot (red) 90
degree relative to load axis. If reusing old bearing,
ensure that scribed line of outer race of the bearing
aligns with the scribed mark on the frame.
JLG INDUSTRIES RECOMMENDS THAT ALL REMOVED GRADE 8
BEARING NUTS AND BOLTS BE DISCARDED AND REPLACED
WITH NEW NUTS AND BOLTS. SINCE THE SWING BEARING IS
THE ONLY STRUCTURAL LINK BETWEEN THE FRAME AND
TURNTABLE, IT IS IMPERATIVE THAT SUCH REPLACEMENT
HARDWARE MEETS JLG SPECIFICATIONS. USE OF GENUINE
JLG HARDWARE IS HIGHLY RECOMMENDED.
6. Apply a light coating of Loctite 271 to the new bear-
ing bolts and loosely install the bolts and washers
through the frame and outer race of bearing.
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.
7. Following the torque sequence diagram shown in
Figure 2-21., Swing Bearing Torquing Sequence,
tighten the bolts to an initial torque of 237 Nm (175
ft. lbs.). Then following the same sequence, tighten
to a final torque of 326 Nm (240 ft. lbs.).
8. Remove lifting equipment from bearing.
9. Use suitable lifting equipment to carefully position
the turntable assembly above the machine frame.
10. Carefully lower the turntable onto the swing bearing.
Ensure that the scribed line of the inner race of the
bearing aligns with the scribed mark on the turnta-
ble. If a new swing bearing is used, ensure that the
filler plug fitting is at 90 degrees from the fore and aft
centerline of the turntable.
11. Apply a light coating of Loctite 271 to the new bear-
ing bolts and install through the turntable and inner
race of bearing.
12. Following the torque sequence shown in Figure 2-
21., Swing Bearing Torquing Sequence, tighten the
bolts to an initial torque of 175 ft. lbs. (237 Nm).
Then following the same sequence, tighten the bolts
to 240 ft. lbs (326 Nm).
13. Remove the lifting equipment.
14. Route hydraulic lines through center of turntable and
frame and connect as tagged prior to removal.
15. Using all applicable safety precautions, activate the
hydraulic system and functionally check swing sys-
tem for proper and safe operation.
Swing Bearing Torque Values
1. Dry - 298 Nm (220 ft. lbs.).
2. Loctite - 326 Nm (240 ft. lbs.).
1
9
13
17
21
3
7
11
15
19
23
10
14
18
22
4
8
12
16
20
24
1
2
2
5
5
9
13
17
3
7
11
15
16
12
8
4
18
14
10
6
6
Figure 2-21. Swing Bearing Torquing Sequence
Updated 11-1-99