SUBSECTION 8E
4. Check the clutch band for distortion and reline it.
GENERAL
This subsection covers the removal, repair, installation and
NOTE
adjustment of the boom hoist clutch.
A lining kit is available. See the Replacement Parts
Manual.
BOOM HOIST CLUTCH (9215J105-1)
5. Check actuating levers (09) and spider (16) for wear. Re-
DESCRIPTION. The boom hoist clutch is located on the end
place it necessary.
of the boom hoist shaft This clutch is hydraulically applied,
6. Inspect the clutch drum to see that it is not cracked,
spring released. When there is no pressure in the clutch cyl-
scored or otherwise damaged.
inder, the return spring applies force to the actuating levers
to contract the band and release the clutch. When the op-
ASSEMBLY AND INSTALLATION. To assemble and install
erator moves the boom hoist control lever to raise or lower
the boom, hydraulic fluid is forced into the cylinder. This
1. Place the clutch band on the spider assembly and attach
causes the piston to extend and apply force on the actuating
springs (05).
levers to expand the band and apply the clutch.
2. Install a new O-ring in the groove of spider (16).
Since lining wear will usually be greatest at the dead end of
the clutch band, the clutch band may be rotated 180 when
3. Install the clutch assembly to the drumshafts and the
wear has reduced the thickness of the lining at the dead end
boom hoist drum.
to 1/4 inch. When wear has reduced the thickness of the
4. Attach the hydraulic swivel to the shaft. Connect the hy-
lining to within 1/16 inch of the rivets, the band should be
draulic lines and bleed cylinder (23) to remove any air trap-
relined.
ped in the lines. See Subsection 5A.
REMOVAL AND DISASSEMBLY. To remove and disassem-
ADJUSTMENT. To adjust the clutch after it has been re-
1. If any rope remains on the boom hoist drum, set the
boom hoist drum pawl to prevent the rotation of the drum.
1. Loosen the jam nuts on all stopscrews (14).
2. Remove any material that may interfere with the
2. Back off on all stopscrews (14) until clutch band (01) is no
removal of the clutch assembly.
longer in contact with the heads of the stopscrews.
3. Loosen jam nuts (15) and turn stopscrews (14) until
3. Adjust setscrew (27) at the dead end of the clutch shoe to
there is adequate clearance around clutch band (01).
approximately 0.058 inch clearance between the clutch
4. Disconnect and cap the hydraulic line to the clutch
lining and the clutch drum, with clutch band guide (18) lo-
swivel. Unscrew the swivel from the shaft.
cated on the top of the clutch.
5. Disconnect the line that runs from cylinder (23) to the
4. Adjust setscrew (04) at the live end of the clutch to ap-
shaft and remove the clutch assembly from the machine.
proximately 0.063 inch of clearance between the clutch lin-
ing and the clutch drum.
6. Remove springs (05) from band (01). The band can now
be removed for relining.
5. Loosen jam nut (25) and turn push rod (24) so the piston
INSPECTION AND REPAIR. Prior to reinstalling the clutch,
in the cylinder (23) is completely retracted with the clutch
control lever in the neutral position.
1. Replace return springs (05).
6. With the clutch in the released position, turn stop-
screws (14) to center the clutch band in the clutch drum.
2. Remove bushing (17) from spider (16) and replace it.
The band must be centered to prevent the lining from
3. If cylinder (23) leaks or has been performing erratically.
rubbing against the drum. There should be no pressure
remove and overhaul or replace it. See Subsection 5D.
against the clutch band from any of the stopscrews.