JLG 80HX_HX+6_HXER Service Manual - Manual (Page 39)

SECTION 2 - PROCEDURES
3120863 – JLG Lift – 2-17
NOTE: Steps 20 thru 23 apply to the Telescope Cylinder
only.
20. Inspect the chain sheave bushings for scoring,
tapering, ovality and for excessive wear and evi-
dence of correct lubrication. Replace the bushing as
necessary.
21. Inspect the sheave chain groove for damage.
Replace the sheave assembly as necessary.
22. Inspect the sheave attach pin for scoring or other
damage and for evidence of correct lubrication.
Dress the pin surface with Scotch Brite or equivalent
or replace the pin as necessary.
23. Inspect the sheave pin lubrication drilling and fitting
for blockage or the presence of dirt or other foreign
material. Repair as necessary.
Assembly
NOTE: Prior to cylinder assembly, ensure that the proper
cylinder seal kit is used. See your JLG Parts Manual.
Apply a light film of hydraulic oil to all components
prior to assembly.
WHEN INSTALLING ‘POLY-PAK’ PISTON SEALS, ENSURE THE
SEALS ARE INSTALLED PROPERLY. REFER TO FIGURE 2-3 FOR
CORRECT SEAL ORIENTATION. IMPROPER SEAL INSTALLATION
COULD RESULT IN CYLINDER LEAKAGE AND IMPROPER CYLIN-
DER OPERATION.
1. For the telescope cylinder only, support the cylinder
rod and install the assembled rod support on the rod
shaft. Push the support along the rod to the port
block end.
2. Place a new wiper seal and rod seal into the applica-
ble cylinder head gland grooves.
3. Carefully install the head gland on the rod, ensuring
that the wiper and rod seals are not damaged or dis-
lodged. Push the head along the rod to the rod end,
as applicable.
4. Carefully slide the piston spacer on the rod. If appli-
cable, align the oil holes in the rod and the spacer.
Secure the spacer, if applicable.
5. If applicable, correctly place a new o-ring and back-
up rings in the inner piston diameter groove.
6. Carefully place the piston on the cylinder rod, ensur-
ing that the o-ring and back-up rings are not dam-
aged or dislodged.
7. Using suitable protection, clamp the cylinder rod in
a vise or similar holding fixture as close to the piston
as possible.
8. Push the piston onto the rod until it abuts the spacer
end and install the attaching nut.
WHEN REBUILDING THE LIFT, SLAVE LEVEL, TELESCOPE,
STEER, AND EXTEND-A-REACH SLAVE AND LIFT CYLINDERS,
APPLY LOCTITE #242 TO PISTON NUT, THEN TIGHTEN BOTH
SECURELY. (SEE TABLE 2-2 FOR TORQUE SPECIFICATIONS).
NOTE: These cylinders use self-locking knurled cup point
setscrews which should be discarded and replaced
whenever they are removed.
After torquing the piston nut spot drill cylinder rod for
setscrews.
9. If applicable, install the setscrew(s) which secure the
piston attaching nut to the diameter groove. (See
Table 2-2 for Torque Specifications).
10. Remove the cylinder rod from the holding fixture.
11. Place new o-rings and seals in the applicable out-
side diameter grooves of both the piston and the cyl-
inder head.
12. Position the cylinder barrel in a suitable holding fix-
ture.
Figure 2-10. Poly-Pak Seal Installation