JLG 600SC_660SJC Service Manual - Manual (Page 93)

SECTION 5 - HYDRAULICS
3120898 – JLG Lift – 5-7
NOTE: When installing the tapered bushing, piston and mat-
ing end of rod must be free of oil.
WHEN REBUILDING THE MASTER, SLAVE, LOWER LIFT, UPPER
LIFT, ARTICULATING FLY BOOM LIFT, UPRIGHT LEVEL, TOWER
TELESCOPE, OR UPPER TELESCOPE CYLINDERS, TIGHTEN
SECURELY. (SEE TABLE 2-1 AND 2-3. TORQUE SPECIFICA-
TIONS).
11. Assemble the tapered bushing loosely into the pis-
ton and insert JLG capscrews (not vendor cap-
screws) through the drilled holes in the bushing and
into the tapped holes in the piston.
12. Tighten the capscrews evenly and progressively in
rotation to the specified torque value. (See Table 5-1,
Cylinder Head and Tapered Bushing Torque Specifi-
cations.
13. After the screws have been torqued, tap the tapered
bushing with a hammer (16 to 24 oz.) and brass
shaft (approximately 3/4" in diameter) as follows;
a. Place the shaft against the cylinder rod and in
contact with the bushing in the spaces between
the capscrews.
b. Tap each space once; this means the tapered
bushing is tapped 3 times as there are 3 spaces
between the capscrews.
14. Retorque the capscrews evenly and progressively in
rotation to the specified torque value. (See Table 5-1,
Cylinder Head and Tapered Bushing Torque Specifi-
cations.)
15. Remove the cylinder rod from the holding fixture.
16. Place new guide locks and seals in the applicable
outside diameter grooves of the cylinder piston.
(See Figure 5-10.)
17. Position the cylinder barrel in a suitable holding fix-
ture.
IMPORTANT
EXTREME CARE SHOULD BE TAKEN WHEN INSTALLING THE
CYLINDER ROD, HEAD, AND PISTON. AVOID PULLING THE ROD
OFF-CENTER, WHICH COULD CAUSE DAMAGE TO THE PISTON
AND CYLINDER BARREL SURFACES.
18. With barrel clamped securely, and while adequately
supporting the rod, insert the piston end into the
barrel cylinder. Ensure that the piston loading o-ring
and seal ring are not damaged or dislodged.
19. Continue pushing the rod into the barrel until the cyl-
inder head gland can be inserted into the barrel cyl-
inder.
Figure 5-11. Tapered Bushing Installation
Figure 5-12. Seating the Tapered Bearing