JLG 600SC_660SJC Service Manual - Manual (Page 244)

SECTION 7 - BOOM & PLATFORM
7-18 – JLG Lift – 3121157
7. Remove the shaft (2) from piston sleeve (3) and the
actuator housing (1).
8. Remove piston sleeve (3) from housing (1).
9. Remove all seals and bearings from grooves. Dis-
card seals.
Inspection
1. Clean all parts thoroughly.
2. Closely inspect all parts for excessive wear, cracks
and chips. Replace parts as necessary.
NOTE: A small amount of wear in the spline teeth will have
little effect on the actuator strength. New spline sets
are manufactured with a backlash of about 0.005 in.
per mating set. After long service, a backlash of
about 0.015 per set may still be acceptable in most
cases, depending on the required accuracy of the
application.
3. Check the ring gear for wear and weld damage to
the pins.
4. Inspect the cylinder bore for wear and scratches.
Assembly
NOTE: Lubricate all seals and o-rings with clean hydraulic
oil prior to assembly.
1. Install new seal (7) and bearing (6) on the piston
sleeve (3).
NOTE: Apply a coat of grease to the thrust ring before slid-
ing onto the shaft.
2. Install new seal (8), thrust ring (10) and bearing (9)
on shaft (2).
NOTE: Apply a coat of grease to the thrust ring before slid-
ing onto the end cap.
3. Install new seals (11), back-up ring (12), cap bearing
(13), bearing packing (14) and thrust ring (10) on
end cap (5).
4. Place the actuator in the vertical position, install the
piston sleeve (3) in timed relation to the housing (1).
DO NOT MISALIGN THE SLEEVE TOO MUCH ANY ONE WAY, AS IT
WILL MARK THE CYLINDER BORE.
NOTE: The timing marks (the small punch marks on the
face of each gear), must be aligned for proper shaft
orientation. (See Actuator Timing.)
5. Install the shaft (2) into housing (1) by aligning the
proper punched timing marks. (See Actuator Tim-
ing.)
6. Temporarily tape the threaded portion of the shaft
will help installation past the shaft seals (masking
tape).
7. The end cap (5) is torqued to 40 - 50 ft. lbs. (54 - 68
Nm), such that the actuator begins rotation at
approximately 100 psi (6.895 Bar) pressure.
Figure 7-24. Removing Shaft from Housing
Figure 7-25. Removing Sleeve from Housing