SECTION 3 - CHASSIS & TURNTABLE
3121171
3-105
3.22 TURNTABLE BEARING
Turntable Bearing Mounting Bolts Condition Check
THE TURNTABLE BEARING IS ONE OF THE MOST CRITICAL POINTS ON AN AER-
IAL LIFT. IT IS HERE STRESSES OF LIFTING ARE CONCENTRATED AT THE CENTER
OF ROTATION. BECAUSE OF THIS, PROPER MAINTENANCE OF THE SWING
BEARING BOLTS IS A MUST FOR SAFE OPERATION.
NOTE:
This check must be performed after first 50 hours of
machine operation and every 600 hours of machine opera-
tion thereafter. If any bolts are missing or loose, replace
with new bolts. Apply JLG Threadlocker PN 0100019 to the
bolt threads and torque to 190 ft-lb (260 Nm). Check all
bolts for looseness after replacing or re-torquing any bolt.
1.
Check frame side bearing bolts as follows:
a.
Raise main boom to be fully elevated and retracted.
Stow tower boom. Raise jib to be fully elevated and
centered. Center platform and keep it unloaded.
(See Figure 3-68.)
b.
At position indicated on Figure 3-68., try to insert a
0.0015 in (0.038 mm) feeler gauge between frame
side bearing bolt and hardened washer.
Figure 3-60. Frame Side Bearing Bolt Location
c.
Ensure 0.0015 in (0.038 mm) feeler gauge will not fit
under bolt head to bolt shank as shown in Figure 3-61.
Figure 3-61. Frame Side Bearing Bolt Feeler Gauge Check
d.
Check a sample of bolts in this 90° quadrant (45° left
and right of indicated position) of the bolt circle.
e.
Swing turntable 90 degrees and check selected
bolts at the new position.
f.
Continue rotating turntable at 90 degree intervals
until a sampling of bolts have been checked in all
quadrants.
2.
Check turntable side bearing bolts as follows:
a.
Raise main boom to be fully elevated and retracted.
Raise Tower boom 10° or enough to gain access to
bearing bolts. Raise jib to be fully elevated and cen-
tered. Center platform and keep it unloaded. (See
Figure 3-69.)
NEVER WORK BENEATH BOOM WITHOUT FIRST ENGAGING BOOM SAFETY
PROP OR PROVIDING ADEQUATE OVERHEAD SLING SUPPORT OR BLOCKING.
b.
At position indicated on Figure 3-69., try to insert a
0.0015 in (0.038 mm) feeler gauge between turnta-
ble side bearing bolt and hardened washer.
Figure 3-62. Turntable Side Bearing Bolt Location
c.
Ensure 0.0015 in (0.038 mm) feeler gauge will not fit
under bolt head to bolt shank as shown in Figure 3-63.
Figure 3-63. Turntable Side Bearing Bolt Feeler Gauge Check
d.
Check a sample of bolts in this 90° quadrant of the
bolt circle (45° left and right of indicated position).
Go
to
Discount-Equipment.com
to
order
your
parts