Skyjack SJ61T, Service Manual

Page: 191 / 232

Telescopic Boom Series
Models SJ61T & SJ66T
194312
December 2007 Page 191
Section 5 - Procedures Service and Maintenance
5.3-8 Check Rotation Bearing for Axial
Wear
1. Position the boom so that it is centered
over the front drive and steer axle and is
horizontal with the ground.
2. Extend the boom to its full extension length.
3. Mount a dial indicator on the chassis. Place
the dial indicator set directly under the
boom, close to the bearing teeth. Make sure
to allow clearance as the turret assembly
rotates.
4. Position the indicator arm or shaft so that
the pointer touches the bottom surface of
the turret weldment.
TURRET
CHASSIS
139314AA ZZ
Check Axial Wear of the Rotation Bearing
5. Zero the dial indicator.
6. Rotate the turret 180° in the clockwise
direction until the boom is centered over
the rear axle. (Rotating the turret in the
counterclockwise direction will cause the
rotation gearbox pinion to impact the dial
indicator).
7. If, when you are rotating the turret, the boom
needs to be retracted or raised to avoid
obstacles, be sure to again fully extend
and level the boom when it is positioned
over the rear axle. Do not be concerned
with any dial indicator readings as the turret
assembly rotates.
8. With the boom assembly rotation stopped
and the boom centered over the rear axle,
read the dial indicator and record the
reading. This reading is the total amount of
axial movement in the bearing assembly. If
this reading is 0.100” (2.54 mm) or greater,
the rotation bearing should be removed and
replaced.