Inspect For Turntable Bearing Wear - Genie TZ-50 Service Manual

September 2014
D-5
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-11, Grease
the Turntable Rotation Bearing and Rotate Gear.
2 Torque the turntable bearing bolts to
specification. See D-4, Check the Turntable
Rotation Bearing Bolts.
3 Start the machine from the ground controls and
raise the primary and secondary booms to full
height. Do not extend the primary boom.
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.
5 At the dial indicator, adjust it to "zero" the
indicator.
Part No. 824982
Section 3 • Scheduled Maintenance Procedures
a
b
c
d
6 Lower the secondary boom to the stowed
position and lower the primary boom to a
horizontal position. Fully extend the primary
boom.
7 Note the reading on the dial indicator.
Result: The measurement is less than
0.025 inch / 0.635 mm. The bearing is good.
Result: The measurement is more than
0.025 inch / 0.635 mm. The bearing is worn and
needs to be replaced.
8 Fully retract the primary boom. Raise the
primary and secondary booms to full height.
Visually inspect the dial indicator to be sure the
needle returns to the "zero" position.
9 Remove the dial indicator and rotate the
turntable 90°.
10 Repeat steps 4 through 9 until the rotation
bearing has been checked in at least four
equally spaced areas 90° apart.
11 Lower the primary and secondary booms to the
stowed position and turn the machine off.
12 Remove the dial indicator from the machine.
Genie TZ-50
CHECKLIST D PROCEDURES
a turntable
b dial indicator
c drive chassis
d turntable rotation bearing
3 - 31