Swing Bearing Replacement - JLG 600SC Service And Maintenance Manual

Swing Bearing Replacement

REMOVAL
1. From Ground Control station, place the boom in a level
position.
NEVER WORK BENEATH THE BOOM WITHOUT FIRST ENGAGING BOOM SAFETY
PROP OR PROVIDING ADEQUATE OVERHEAD SLING SUPPORT AND/OR BLOCK-
ING.
2. Adequately secure the boom to the rear of the turntable,
as shown in Figure 3-14., Swing Bearing Removal -
600SC and Figure 3-15., Swing Bearing Removal -
660SJC.
3. Using the front lifting eyes in the turntable and a loca-
tion on the boom equidistant from the center of gravity,
as shown in Figure 3-14., Swing Bearing Removal -
600SC and Figure 3-15., Swing Bearing Removal -
660SJC, secure the turntable assembly with adequate
lifting equipment.
4. 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 THE ENTRY OF CONTAMINANTS INTO THE SYS-
TEM.
5. Tag and disconnect hydraulic lines from the fittings on
the top of the rotary coupling. Use a suitable container
to retain any residual hydraulic fluid. Immediately cap
lines and ports.
6. Use a suitable tool to scribe a line on the inner race of
the swing bearing and on the underside of the turnta-
ble. This will aid in aligning the bearing upon installa-
tion. Remove the bolts and washers which attach the
turntable to the bearing inner race. Discard the bolts.
7. Use the lifting equipment to carefully lift the complete
turntable assembly from the bearing. Ensure that no
damage occurs to the turntable, bearing or frame-
mounted components.
8. Carefully place the turntable on a suitably supported
trestle.
9. Use a suitable tool to scribe a line on the outer race of
the swing bearing and the frame. This line will aid in
aligning the bearing upon installation. Remove the bolts
and washers which attach the outer race of the bearing
to the frame. Discard the bolts. Use suitable lifting
equipment to remove the bearing from the frame, then
move the bearing to a clean, suitably supported work
area.
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SECTION 3 - CHASSIS & TURNTABLE
INSTALLATION
1. Using suitable lifting equipment, carefully lower the
swing bearing into position on the frame. Ensure the
scribed line of the outer race of the bearing aligns with
the scribed line on the frame. If a new swing bearing is
used, ensure that the filler plug fitting is at 90 degrees
from the fore and aft center line of the frame.
JLG INDUSTRIES RECOMMENDS ALL REMOVED BEARING BOLTS BE DISCARDED
AND REPLACED WITH NEW BOLTS. SINCE THE SWING BEARING IS THE ONLY
STRUCTURAL LINK BETWEEN THE FRAME AND TURNTABLE, IT IS IMPERATIVE
SUCH REPLACEMENT HARDWARE MEETS JLG SPECIFICATIONS. USE OF GENU-
INE JLG HARDWARE IS HIGHLY RECOMMENDED.
2. Apply a light coating of JLG Threadlocker P/N 0100019
to the new bearing bolts, and loosely install the bolts
and washers through the frame and outer race of bear-
ing.
IF COMPRESSED AIR OR ELECTRICALLY OPERATED IMPACT WRENCH IS USED
FOR TIGHTENING THE BEARING ATTACHMENT BOLTS, THE TORQUE SETTING
ACCURACY OF THE TOOL SHOULD BE CHECKED PRIOR TO USE.
3. Refer to the Torque Sequence diagram as shown in Fig-
ure 3-13., Swing Bearing Torque Sequence, Swing Bear-
ing Torque Sequence Clean any residue off the new
bearing bolts, then apply a light coating of JLG Thread-
locker P/N 0100019 and install the bolts and washers
through the frame and outer race of the bearing.
Tighten the bolts to an initial torque of 190 ft. lbs. (260
Nm) w/Loctite.
4. Remove the lifting equipment from the bearing.
5. Using suitable lifting equipment, carefully position the
turntable assembly above the machine frame.
6. Carefully lower the turntable onto the swing bearing,
ensuring that the scribed line of the inner race of the
bearing aligns with scribed line 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 center line of
the turntable.
7. Clean any residue off the new bearing bolts, then apply
a light coating of JLG Threadlocker P/N 0100019 and
install the bolts and washers through the turntable and
inner race of the bearing.
8. Following the Torque Sequence diagram shown in Fig-
ure 3-13., Swing Bearing Torque Sequence, tighten the
bolts to a torque of 190 ft. lbs. (260 Nm) w/Loctite.
9. Install the rotary coupling retaining yoke brackets, apply
a light coating of JLG Threadlocker P/N 0100011 to the
attaching bolts and secure the yoke to the turntable
with the mounting hardware.
10. Connect the hydraulic lines to the rotary coupling as
tagged prior to removal.
3-17