Inspect For Turntable Bearing Wear - Genie Z80/60 Service Manual

June 2012
REV E
D-4
Inspect for Turntable Bearing
Wear
Periodic inspection of turntable bearing wear is
essential to safe machine operation, good machine
performance and service life. Continued use of a
worn turntable bearing could create an unsafe
operating condition, resulting in death or serious
injury and component damage.
Note: Perform this procedure with the machine on
a firm, level surface and the boom in the stowed
position.
1 Grease the turntable bearing. See A-10, Grease
the Turntable Bearing and Rotate Gear.
2 Torque the turntable bearing bolts to
specification. See D-3, Check the Turntable
Rotation Bearing Bolts.
3 Start the machine from the ground controls and
fully elevate, but do not extend, the primary
boom and jib. The riser should remain in its
stowed position.
4 Place a dial indicator between the drive chassis
and the turntable at a point that is directly
under, or inline with, the boom and no more
than 1 inch / 2.5 cm from the bearing.
Note: To obtain an accurate measurement, place
the dial indicator no more than 1 inch / 2.5 cm from
the turntable rotation bearing.
Part No. 88619
Section 3 • Scheduled Maintenance Procedures
CHECKLIST D PROCEDURES
a
b
c
d
a
b
c
d
5 Adjust the dial indicator need to the "zero"
position.
6 Elevate the riser, but do not extend it. Move the
primary boom and jib to horizontal and fully
extend.
7 Note the reading on the dial indicator.
Result: The measurement is less than
0.063 inch / 1.6 mm. The bearing is good.
Result: The measurement is more than
0.063 inch / 1.6 mm. The bearing is worn and
needs to be replaced.
8 Move the boom sections to the positions
indicated in step 3. Visually inspect the dial
indicator to be sure the needle returns to the
"zero" position.
Z-80/60
turntable
dial indicator
drive chassis
turntable rotation bearing
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