SECTION 3 - CHASSIS & TURNTABLE
3121171
3-111
Turntable Bearing Removal
1.
From Ground Control Station, elevate tower boom to
about 10° or enough to gain access to bearing bolts. Set
main boom horizontal and fully retracted. Raise and
center jib and platform. (See Figure 3-71.)
NEVER WORK BENEATH BOOM WITHOUT FIRST ENGAGING BOOM SAFETY
PROP OR PROVIDING ADEQUATE OVERHEAD SLING SUPPORT OR BLOCKING.
2.
Attach an adequate support sling to the boom. Remove
all slack from sling. Prop or block boom if possible.
3.
From inside turntable, remove mounting hardware
attaching rotary coupling retaining yoke brackets to
turntable.
HYDRAULIC LINES AND PORTS SHOULD BE CAPPED IMMEDIATELY AFTER DIS-
CONNECTING LINES TO AVOID ENTRY OF CONTAMINANTS INTO THE SYSTEM.
4.
Tag and disconnect hydraulic lines from fittings on top
of rotary coupling. Use a suitable container to retain any
residual hydraulic fluid. Immediately cap lines and ports.
5.
Attach suitable overhead lifting equipment to base of
turntable.
6.
Scribe a line on the turntable bearing inner race and
underside of turntable. This will aid in aligning the bear-
ing during re-installation. Remove bolts and washers
attaching turntable to bearing inner race. Discard bolts.
7.
Carefully lift complete turntable assembly from bearing.
Ensure no damage occurs to turntable, bearing, or
frame-mounted components. Refer to Figure 3-71.,
Turntable Bearing Removal.
8.
Carefully place turntable on a suitably supported trestle.
9.
Scribe a line on turntable bearing outer race and frame.
This helps align the bearing during re-installation.
Remove bolts and washers attaching bearing outer race
to the frame. Discard bolts.
10.
Use suitable lifting equipment to remove bearing from
frame. Move bearing to a clean, suitably supported work
area.
Turntable Bearing Installation
1.
Using suitable lifting equipment, carefully lower turnta-
ble bearing into position on frame. Ensure scribed line of
bearing outer race aligns with scribed line on frame. If a
new turntable bearing is used, ensure spot with mini-
mum gear backlash (stamped with an “X” or marked
with yellow paint) is towards centerline of the swing
drive (as close as bolt pattern allows).
JLG INDUSTRIES RECOMMENDS DISCARDING ALL REMOVED BEARING BOLTS
AND REPLACING WITH NEW BOLTS. SINCE THE TURNTABLE BEARING IS THE
ONLY STRUCTURAL LINK BETWEEN FRAME AND TURNTABLE, IT IS IMPERA-
TIVE THAT SUCH REPLACEMENT HARDWARE MEETS JLG SPECIFICATIONS. USE
OF GENUINE JLG HARDWARE IS HIGHLY RECOMMENDED.
2.
Spray a light coat of Safety Solvent 13 on new bearing
bolts.
3.
Apply a light coating of JLG Threadlocker PN 0100019 to
new bearing bolts. Loosely install bolts and washers to
frame and bearing outer race.
IF COMPRESSED AIR OR ELECTRICALLY OPERATED IMPACT WRENCH IS USED
FOR TIGHTENING BEARING ATTACHMENT BOLTS, CHECK TOOL TORQUE SET-
TING ACCURACY BEFORE USE.
4.
Torque bolts to 190 ft-lb (260 Nm) in sequence shown in
Figure 3-72., Turntable Bearing Torque Sequence.
5.
Remove lifting equipment from bearing.
6.
Using suitable lifting equipment, carefully position turn-
table assembly above machine frame.
7.
Carefully lower turntable onto turntable bearing, ensur-
ing scribed line on bearing inner race aligns with scribed
line on turntable. If a new turntable bearing is used,
ensure filler plug fitting is at 90 degrees from fore and
aft center line of turntable.
8.
Spray a light coat of Safety Solvent 13 on new bearing
bolts.
9.
Apply a light coating of JLG Threadlocker PN 0100019 to
new bearing bolts. Install bolts and washers to turntable
and bearing inner race.
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