JLG 120-SXJ ANSI Service Manual - Manual (Page 29)

SECTION 3 - CHASSIS & TURNTABLE
3121105 – JLG Lift – 3-1
SECTION 3. CHASSIS & TURNTABLE
3.1 DRIVE HUB
The final drive consists of two planetary stages with an
integrated disconnect mechanism. Each stage incorpo-
rates a set of matched planetary gears, which provide an
equal load distribution. All torque transmitting compo-
nents are made of forged quenched and tempered high-
alloy steels. External gears are carburized. Precision roller
bearings support the sprocket or wheel loads. A shaft seal
protects the unit against contamination.
Disassembly
1. Position drive so that one of the fill holes is at the
bottom of the end cover and drain the oil.
2. Remove all bolts holding the motor and Remove
motor from drive.
3. Compress the spring (55) using a simple fixture or
other suitable device.
4. Remove snap ring (66) and release pressure on the
spring (55) until loose.
5. Remove the spring (55).
6. Turn unit so that cover (8) is in the up position.
7. Remove the screw plugs (21) and seal rings (22).
8. Remove “o” ring (33).
9. Remove the first stage planetary assembly (7).
10. Remove hex bolts (23).
12. Remove ring gear (30) and “o” ring (19).
13. Remove snap rings (15).
14. Pull off planet gears (1) together with cylindrical
roller bearings (11) from spindle (60).
NOTE: Further disassembly of the hub is discouraged. rein-
stallation of the shaft nut (4) requires a special tool
and a torque of 626 ft./ lbs. (876 Nm) for proper reas-
sembly. These components Will Fail if not properly
reassembled.
15. Inspect the planetary stage assemblies as complete
units. Thoroughly clean and check both the gearing
and the bearings for damage and apply new oil. If
the gears or bearings need replacing, they must be
replaced as complete sets.
16. The first stage planetary gears (2) must be changed
in sets of three pieces.
17. The first stage planetary gears (2) must be changed
as a complete set of three and JLG recommends
changing the sun gear shaft (43) along with this set
of planets.
18. The second stage planetary bearings (11) must be
replaced in sets of four pieces.
19. The second stage planetary gears (1) must be
changed as a complete set of four and JLG recom-
mends changing the sun gear (3) along with this set
of planets.
Disassembly of Cover
Loosen and remove hex head bolts (53) to remove cover
(51).
Disassembly of the First Stage Planetary
Assembly (7)
1. Push sun gear shaft (43) out of the first stage.
2. Remove snap rings (14).
3. Press planet pins (5) out of the planet gears (2).
4. Pull cylindrical roller bearing (10) out of the planet
gears (2).
5. Remove snap ring (16) from sun gear (3) and
Remove planet carrier (7) from sun gear (3).
Disassembly of Second Stage Planet Gears
(1)
Press cylindrical roller bearings out of planet gears (1).