Manitowoc National Crane NBT30H-2, Service Manual

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SWING NBT30H-2 SERVICE MANUAL
6-4
03-20-2019 Control # 613-06
SWING GEARBOX AND BRAKE
The swing drive is a double planetary gear set with an
integral brake. The swing drive is designed to give long life in
heavy duty applications such as crane rotation.
NOTE: Motor and cartridge valves are not serviceable in
the field. Return them to an authorized distributor
for service.
Disassembly and Assembly Instructions
Use the following procedure for swing drive disassembly.
NOTE: The weight of the rotation gearbox with integral
brake and a hydraulic motor bolted on the input end
of the assembly is approximately 275 lbs (124 kg).
Tools Required
• Scribe or small punch
• Oil drain pan
• Eye bolts 1/4"
• Retaining ring pliers
• Gear puller
• Ratchet wrench (1/2" drive)
• 9/16" socket (1/2" drive)
• Socket for pinion nut (Whittet-Higgins P/N BAS-14)
• Soft hammer (brass or plastic)
• Press
• Drift rod (6 to 10 mm (0.25 in to 0.375 in) diameter)
• Torque wrench [1/2” drive - approximately 135 N·m (100
ft-lb)]
Gearbox Disassembly
(See Figure 6-2 for reference numbers.)
1. Remove the swing drive from the crane and remove the
swing motor from the swing drive.
2. Drain the oil from the gearbox by removing the drain
plug (17).
3. Scribe a mark on the brake assembly flange (15) and the
top edge of the gear housing (1) to aid in reassembly.
4. Remove the eight capscrews (16) holding the brake
assembly (15) onto the gear housing (1).
5. Lift the brake assembly (15) off of the gear housing (1).
6. Inspect the brake housing O-ring (14) and replace if
necessary.
7. Remove the race (11a) from the input planetary
assembly (13).
8. Install three 1/4” eyebolts into the three planet pins of the
input planetary assembly (13) and with a small chain pull
the planet set from the gear housing.
9. Remove the output sun gear (12) and race (11b) from
the output planetary assembly (10).
10. Using the eyebolt/chain method outlined in step 6,
remove the output planetary assembly (10) from the
gear housing.
11. Remove the lockwasher (8) and locknut (9).
12. Remove the pinion shaft (2) from the housing (1).
The unit is now disassembled into groups of parts. The
area(s) requiring repair should be identified by thorough
inspection of the parts after they have been washed in
solvent, then refer to the appropriate group repair section.
Input Planetary Repair
(See Figure 6-2 for reference number identification.)
1. Remove the retaining washers (26) from the planet pins.
2. Press the planet pins (27) out of the carrier (13).
3. Slide planet gears (25) and races (28) out of the input
carrier (13).
4. Remove the plate (30) from the input carrier (13).
5. If needle bearings (29) must be replaced, they may now
be removed out of the input planet gears (25).
6. Rebuild input gear set in reverse order using any
required new parts.
7. Before reassembly, be sure to insert the plate (30) into
the input carrier (13).
8. To reassemble, be careful to line up the planet pins (27)
with the races (28) and the bearings (29) and then press
the knurled part of the planet pin (27) into the input
carrier (13). If the planet pins (27) are not lined up
properly, the races (28) can be shattered during the
pressing process. Reinstall the retaining washers (26)
onto the planet pins.
Output Planetary Repair
(See Figure 6-2 for reference number identification.)
Repair for the output planetary gear set is the same as the
input planetary gear set with one exception. The output
planetary gear set has two needle bearings (22) per
planetary pin (20) with a spacer (23) between the bearings.