JLG 800A_AJ Service Manual - Manual (Page 104)

SECTION 3 - CHASSIS & TURNTABLE
3-48 – JLG Lift – 3120858
h. Carefully place the turntable on a suitably sup-
ported trestle.
i. 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 installa-
tion. 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.
2. Installation.
a. 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 THAT 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 THAT SUCH
REPLACEMENT HARDWARE MEETS JLG SPECIFICATIONS. USE
OF GENUINE JLG HARDWARE IS HIGHLY RECOMMENDED.
b. 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 ATTACHMENT
BOLTS, THE TORQUE SETTING ACCURACY OF THE TOOL SHOULD
BE CHECKED PRIOR TO USE.
c. Refer to the Torque Sequence diagram as
shown in Figure 3-37., Swing Bearing Torque
Sequence. Clean any residue off the new bear-
ing bolts, then apply a light coating of Loctite
#271 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.
d. Remove the lifting equipment from the bearing.
e. Using suitable lifting equipment, carefully posi-
tion the turntable assembly above the machine
frame.
f. 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 fitting is at 90 degrees
from the fore and aft center line of the turntable.
g. Clean any residue off the new bearing bolts,
then apply a light coating of Loctite #271 and
install the bolts and washers through the turnta-
ble and inner race of the bearing.
h. Following the Torque Sequence diagram shown
i n F i g u r e 3 - 3 7 . , S w i n g B e a r in g Tor qu e
Sequence, tighten the bolts to a torque of 190 ft.
lbs. (260 Nm) w/Loctite.
i. Remove the lifting equipment.
j. Install the rotary coupling retaining yoke brack-
ets, apply a light coating of Loctite #242 to the
attaching bolts and secure the yoke to the turn-
table with the mounting hardware.
k. Connect the hydraulic lines to the rotary cou-
pling as tagged prior to removal.
l. At ground control station, use boom lift control
to lower boom to stowed position.
m. Using all applicable safety precautions, activate
the hydraulic system and check the swing sys-
tem for proper and safe operation.
Swing Bearing Torque Values
1. Outer Race - 190 ft. lbs. (260 Nm) w/Loctite.
2. Inner Race - 190 ft. lbs. (260 Nm) w/Loctite.
3. See Swing Bearing Torquing Sequence.
CHECK THE INNER AND OUTER SWING BEARING BOLTS FOR
MISSING OR LOOSENESS AFTER FIRST 50 HOURS OF OPERA-
TION, AND EVERY 600 HOURS THEREAFTER.