JLG 25RTS, Service & Maintenance

Page: 40 / 84

SECTION 2 - PROCEDURES
2-24 – JLG Sizzor – 3120826
THE FOLLOWING PROCEDURE SHOULD BE USED IF THE
SPRING IS TO BE REMOVED FROM THE PISTON BLOCK. THE
SPRING IS HIGHLY COMPRESSED AND THE SNAP RING SHOULD
NOT BE REMOVED WITHOUT COMPRESSING THE SPRING.
9. Disassemble the piston block as follows:
NOTE: The following parts will be needed to disassemble
the piston block:
2 ea. 3/8 I.D. x 1-1/8 O.D. flat washers
1 ea. 3/8 x 3-1/4 N.C. cap screw
1 ea. 3/8 N.C. nut
a. Place one of the flat washers over the 3/8 x 3-1/4
cap screw and place this through the center of
the piston block.
b. Place the other washer over the cap screw and
let it rest on the three pins.
c. Screw nut on cap screw and compress the
spring inside the piston block.
d. Using a pair of snap ring pliers, remove internal
snap ring.
e. Remove bolt, nut, and two washers.
f. Remove two washers, spring, three pins, and
pin keeper.
10. Remove thrust race, shaft seal, washer, and drive
shaft from housing.
11. Remove two snap rings, thrust washers, and thrust
bearing from drive shaft.
Inspection
1. Wash all parts thoroughly in a suitable solvent.
2. Examine needle bearings in housing and back plate.
If needles are free of excessive play and remain in
bearing cage, there is no need to replace bearing.
3. Inspect thrust washers and thrust bearing. All sur-
faces should be free of any signs of wear or fretting.
4. Inspect spider and pivot. Conical surfaces should be
free of wear and score marks.
5. Inspect pistons. The O.D. surface should be smooth
and free of scoring. Shoes should be snug fit to pis-
ton. Face of shoes should be flat and free of scoring
and flaking. Do not lap piston shoes.
6. Inspect piston block; bores should be free of scor-
ing. Surface that contacts back plate should be
smooth and free of grooves or metal build-up. Do
not lap piston block.
7. Inspect thrust race; surface should show no signs of
scoring or grooves.
8. Inspect flat surface on back plate; it should be free
of excessive scoring or metal build-up. Do not lap
back plate.
9. Inspect drive shaft for fretting in bearing areas.
Check spline area for twisted or broken teeth. If
keyed shaft, check for cracked or chipped keyway.
Assembly
NOTE: Use filtered system oil to lubricate all critical moving
parts before assembly.
1. Install one snap ring in rear groove of drive shaft
Install one thrust washer, thrust bearing, and second
thrust washer on drive shaft. Install second snap ring
in front groove on drive shaft.
2. Replace needle bearing in housing if necessary.
Install shaft in housing assembly and install washer .
Oil I.D. of new shaft seal and press into position.
Retain with snap ring.
3. Compress pin keeper and install in spline area of
piston block.