JLG 660SJ ANSI Service Manual - Manual (Page 96)

SECTION 3 - CHASSIS & TURNTABLE
3-42 – JLG Lift – 3120718
2. Check the turntable to bearing. Attach bolts as fol-
lows:
a. Elevate the fully retracted boom to 70 degrees
(full elevation).
b. At the positions indicated on Figure 3-27. try and
insert the 0.0015" feeler gauge between the bolt
head and hardened washer at the arrow indi-
cated position.
c. Lower the boom to horizontal and fully extend
the boom.
d. At the position indicated on Figure 3-27. try and
insert the 0.0015" feeler gauge between the bolt
head and hardened washer at the arrow indi-
cated position.
Wear Tolerance (S & A Models)
1. From the underside of the machine, at rear center,
with the boom fully elevated and fully retracted, as
shown in Figure 3-28., Swing Bearing Tolerance
Boom Placement (S Models) and Figure 3-29.,
Swing Bearing Tolerance Boom Placement (A Mod-
els) - Swing Bearing Tolerance Boom Placement) A,
using a magnetic base dial indicator, measure and
record the distance between the swing bearing and
turntable. (Figure 3-30., Swing Bearing Tolerance
Measuring Point)
2. At the same point, with the boom at horizontal and
fully extended, and the tower boom fully elevated as
shown in (Figure 3-29., Swing Bearing Tolerance
Boom Placement (A Models) - Swing Bearing Toler-
ance Boom Placement) B, using a magnetic base
dial indicator, measure and record the distance
between the swing bearing and turntable. (Figure 3-
30., Swing Bearing Tolerance Measuring Point)
3. If a difference greater than 0.057 in. (1.40 mm) is
determined, the swing bearing should be replaced.
4. If a difference less than 0.057 in. (1.40 mm) is deter-
mined, and any of the following conditions exist, the
bearing should be removed, disassembled, and
inspected for the following:
a. Metal particles in the grease.
b. Increased drive power required.
c. Noise.
d. Rough rotation.
Figure 3-26. Swing Torque Hub Adjustment
.0015" Feeler Gauge
Figure 3-27. Swing Bearing Bolt Feeler Gauge Check