JLG 510AJ Service Manual - Manual (Page 106)

SECTION 3 - CHASSIS AND TURNTABLE
3-64 – JLG Lift – 3121181
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 RECOM-
MENDED.
6. Apply a light coating of Loctite 271 to the new bearing
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
3-52., Swing Bearing Torque Sequence, tighten the bolts
to an initial torque of 175 ft. lbs. (237 Nm). Then follow-
ing the same sequence, tighten to a final torque of 240
ft. lbs. (326 Nm).
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 bear-
ing aligns with the scribed mark on the turntable. If a
new swing bearing is used, ensure that the filler plug fit-
ting is at 90 degrees from the fore and aft centerline of
the turntable.
11. Apply a light coating of Loctite 271 to the new bearing
bolts and install through the turntable and inner race of
bearing.
12. Following the torque sequence shown in Figure 3-52.,
Swing Bearing Torque 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 system
for proper and safe operation.
Turntable Bearing Mounting Bolt Condition Check
NOTE: This check is designed to replace the existing bearing bolt
torque checks on JLG Lifts in service. This check must be
performed after the first 50 hours of machine operation
and every 600 hours of machine operation thereafter. If
during this check any bolts are found to be missing or
loose, replace missing or loose bolts with new bolts and
torque to the value specified in the torque chart, after lubri-
cating the bolt threads with loctite #271. After replacing
and retorquing bolt or bolts recheck all existing bolts for
looseness.
Check the frame to bearing. Attach bolts as follows:
1. Elevate the fully retracted boom to 70 degrees (full ele-
vation).
2. At the positions indicated on the figure titled Swing
Bearing Tolerance Boom Placement. Try and insert the
0.0015" feeler gauge between the bolt head and hard-
ened washer at the arrow indicated position.
3. Assure that the 0.0015" feeler gauge will not penetrate
under the bolt head to the bolt shank.
4. Swing the turntable 90 degrees, and check some
selected bolts at the new position.
5. Continue rotating the turntable at 90 degrees intervals
until a sampling of bolts have been checked in all quad-
rants.
Check the turntable to bearing. Attach bolts as follows:
1. Elevate the fully retracted boom to 70 degrees (full ele-
vation).
2. At the positions indicated in the figure below, try and
insert the 0.0015" feeler gauge between the bolt head
and hardened washer at the arrow indicated position.
.0015" Feeler Gauge
Figure 3-50. Swing Bearing Feeler Gauge Check