SUBSECTION 7D
CLUTCHES
GENERAL
2. Remove bushing (20) from spider (19) and replace it.
This subsection contains the information necessary to re-
3. If cylinder (21) leaks or has been performing erratically,
move, repair, install and adjust the left and rightdrum
remove, overhaul, and/or replace it. See Subsection 5D.
clutches.
4. Check the clutch band for distortion and reline it.
MAIN DRUM CLUTCHES (2915J64)
NOTE
DESCRIPTION. The left and right drum clutches are located
A lining kit
available. See the Replacement Parts
IS
on the ends of the hoist drumshaft. These clutches are hy-
Manual.
draulically applied, spring released. When there is no pres-
sure in the clutch cylinder, the return spring applies force to
5. Check actuating levers (09), trunnion (10) and spider (19)
the actuating levers to contract the band and release the
for wear. Replace if necessary.
clutch. When the operator moves a clutch control lever to
6. Remove spring (26) by turning out eyebolt (11). Check
apply a clutch, hydraulic fluid is forced into the cylinder.
the compression quality of the spring. If acceptable, as-
This causes the piston to extend and apply force on the
semble to the clutch spider Preload spring (26) to 5-1/2
actuating levers to expand the band and apply the clutch.
inches.
Since the lining will wear with time and constant usage, a
periodic check must be made to determine the need for re-
ASSEMBLY AND INSTALLATION To assemble and install
placing the lining. When wear has reduced the lining to
the clutch, proceed as follows (see Figure 7D-1):
within 1/16 inch of the rivets, it should be replaced. This
1. Assemble band (01) with two shims (28), lockwashers
distance would amount to 7/32 inch measured from the
(29) and nuts (30).
outside.
REMOVAL AND DISASSEMBLY. To remove and disassem-
NOTE
ble the clutch, proceed as follows (see Figure 7D-1):
Shims (28) can be used to adjust the clutch when
1. If any rope remains on the drum to be worked on, set the
linings are worn.
drum pawl to prevent the rotation of the drum.
2. Remove any material that may interfere with the re-
2. Place the clutch band on the spider assembly and attach
moval of the clutch assembly.
springs (05).
3. Loosen jam nuts (15) and turn in stopscrews (14) until
3. Insert O-ring (37) in the groove of the hub.
there is adequate clearance around the clutch band (01).
4. Attach the clutch assembly to the drumshaft.
4. Disconnect and cap the hydraulic line to the clutch
5. Attach the hydraulic swivel to the shaft. Connect the hy-
swivel. Unscrew the swivel from the drumshaft.
draulic lines and bleed cylinder (21) to remove any air trap-
5. Disconnect the line that runs from cylinder (21) to the
ped in the lines (see Subsection 5A).
drumshaft and remove the clutch assembly from the ma-
chine.
ADJUSTMENT. To adjust the clutch after it has been re-
moved, proceed as follows (see Figure 7D-1):
6. Remove springs (05) from band (01). Remove nuts (30)
from capscrews (27) and remove shims (28) The band, in
1. Loosen the jam nuts on all stopscrews (14).
two pieces, can now be removed for relining.
2. Backoff on all stopscrews (14) until clutch band (01) is no
7. Inspect the clutch drum to see that it is not cracked,
longer in contact with the heads of the stopscrews.
scored or otherwise damaged.
3. Adjust setscrew (23) at the dead end of the clutch shoe
INSPECTION AND REPAIR. Prior to reinstalling the clutch,
so that there is approximately 0.030 inch clearance be-
inspect and repair the following items (see Figure 7D-1):
tween the clutch lining and the clutch drum, with clutch
band guide (16) located on the top of the clutch.
1. Replace return springs (05).
