JLG 25RTS, Service & Maintenance

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SECTION 2 - PROCEDURES
2-38 – JLG Sizzor – 3120826
Roll Test
The purpose of a roll test is to determine if the unit’s gears
are rotating freely and properly. Gears should be able to
be rotated by applying a constant force to the roll checker.
If more drag is felt in the gears only at certain points, then
the gears are not rolling freely and should be be examined
for proper installation or defects. Some gear packages roll
with more difficulty than others. Do not be concerned if
gears seem to roll hard as long as they roll with consis-
tency.
Leak Test
The purpose of the leak test is to make sure the unit is air
tight. The unit has a leak if the pressure gauge reading on
the air checker starts to fall once the unit has been pres-
surized. Leaks will most likely occur at main seal or wher-
ever o-rings or gaskets are located. The exact location of
a leak can usually be detected by brushing a soap and
water solution around the main seal and where o-rings or
gaskets meet the exterior of the unit, then checking for air
bubbles. If a leak is detected in a seal, o-ring, or gasket,
the part must be replaced.
Assembly
1. Grease o-ring.
2. Place o-ring into counter bore in hub.
BEWARE OF SHARP EDGES AND BURRS IN COUNTER BORE
WHEN INSTALLING O-RING.
NOTE: O-rings may be stretched to fit counter bore. If an o-
ring has been stretched too much, simply squeeze o-
ring together bit by bit while placing it around counter
bore. It can be made to fit exactly.
3. Oil exposed surfaces inside hub.
4. Mark four shoulder bolt holes on hub so for align-
ment with shoulder bolt holes in ring gear and cover.
5. Place internal gear into hub so its internal splines
mesh with external splines of spindle/brake.
6. Oil internal gear.
7. Place thrust washer onto spindle/brake so it rests on
bottom of internal gear.
8. Assemble input shaft as follows:
a. Place one spacer, spring, and other spacer, IN
THAT ORDER, onto smooth end of shaft.
SAFETY GLASSES SHOULD BE WORN DURING FOLLOWING
PROCEDURE.
b. Place retaining ring onto input shaft. Using
retaining ring pliers, insert retaining ring into
groove on input shaft by compressing spring
and spacers together.
9. With large, splined end down, place input shaft
assembly into spindle/brake.
10. Place thrust spacer onto input shaft.
11. With internal splines facing up, place input gear into
mesh with input shaft assembly.
12. Assemble carrier as follows:
a. Apply grease to inside of one cluster gear.
b. Line one half of cluster gear with 16 needle roll-
ers.
c. Place one spacer inside cluster gear so it rests
on top of needle rollers.
d. Line remaining half of cluster gear with 16 nee-
dle rollers.
e. Insert a planet shaft into one of the planet shaft
holes in the carrier housing which has a roll pin
hole. End of planet shaft that does not have a
roll pin hole should be inserted into carrier hous-
ing first.
f. Place one thrust washer onto end of planet shaft
which has been inserted through planet shaft
hole. Notice that thrust washer has a tang on it.
Tang should point straight so as to fit in slot on
inside edge of planet shaft hole.
g. Following thrust washer, place cluster gear, with
needle rollers, onto planet shaft. Large end of
cluster gear should go onto shaft first.
h. Following cluster gear, place one more thrust
washer onto planet shaft. Align thrust washer in
same manner as described in step (f).
i. Insert planet shaft through opposite planet shaft
hole in carrier housing. Use an alignment punch
or similar tool to align roll pin holes in carrier
housing and planet shaft.
j. Drive roll pin down into aligned roll pin holes.
k. Repeat steps (a) through (j) to install two remain-
ing cluster gears.