Oshkosh JLG 400S, Service And Maintenance Manual

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SECTION 3 - CHASSIS & TURNTABLE
3120895 – JLG Lift – 3-5
3.3 DRIVE HUB PART NO. 2780246 (4WD
STEER AXLE PRIOR TO S/N
0300076633)
The final drive consists of two stages with an integrated
disconnect mechanism. Each stage incorporates a set of
matched planetary gears, which provide an equal load of
distribution. All torque transmitting components are made
of forged, quenched and tempered high-alloy steels.
External gears are carborized. Precision roller bearings
are used exclusively. Two large, tapered 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 gear oil.
2. Remove all bolts holding motor and remove motor
from drive.
3. Compress the disc (59) using a simple fixture or
other suitable device.
4. Remove snap ring (66) and release pressure on disc
until loose. Remove tool and disc (59).
5. Remove the spring (55) from the input shaft (44)and
turn the unit so that cover (8) is in the up position.
6. Remove screw plugs (22) and seal rings (21).
7. Remove snap ring (34), cover unit (8) from drive and
O-ring (33).
8. Remove first stage planetary assembly (7).
9. Remove hex. hd. bolts (23) to remove gear (33) and
O-ring (19).
10. Remove Snap rings (15) to 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.
11. 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
gears or bearings need replacing, they must be
replaced as complete units.
NOTE: The first stage planetary bearings (10) must be
replaced in sets of three pieces.
NOTE: The first stage planetary gears (11) must be
changed as a complete set of four and the manufac-
turer recommends changing the sun gear shaft (43)
along with this set of planets.
NOTE: The second stage planetary bearings (11) must be
replaced in sets of four pieces.
Disassembly of Cover Unit (8)
1. Loosen and remove hex. hd. bolts (53) and remove
cover (51).
2. Remove Shaft rod (56), O-ring (54), and sleeve (52)
Disassembly of First Stage Planetary
Assembly
1. Push the sun gear shaft (43) out of the first stage.
2. Remove snap rings (14) and press planet pins (5)
out of planet carrier (7) and planet gears (2).
3. Pull cylindrical roller bearing (10) out of planet gears
(2).
4. Remove snap ring (16) from sun gear (3) and
remove the thrust washer (49).
Disassembly of the Second Stage Planet
Gears (1)
Press cylindrical roller bearings out of planet gears (1).