Genie Z-30/20N Service Manual page 46

Section 3 • Scheduled Maintenance Procedures
CHECKLIST D PROCEDURES
4 Place a dial indicator between the drive chassis
and the turntable at a point that is directly
under, or in line 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.
a
b
c
d
a turntable
b dial indicator
c drive chassis
d turntable rotation bearing
5 Adjust the dial indicator to "0".
6 Lower the secondary boom to the stowed
position and lower the primary boom to a
horizontal position. Fully extend the primary
boom.
3 - 28 Z-30/20N • Z-30/20N RJ • Z-34/22 • Z-34/22N
7 Note the reading on the dial indicator.
Result: The measurement is less than
0.055 inch / 1.4 mm. The bearing is good.
Result: The measurement is more than
0.055 inch / 1.4 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 "0" 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.
June 2011
REV A
Part No. 139378