Reference
Only
Manitowoc
Published 01-08-13, Control # 049-05
6-17
2250 MAX-ER 2000 OPERATOR’S MANUAL
MAINTENANCE
6
MAIN LOAD DRUM RATCHET AND PAWL
ADJUSTMENT
See Figure 6-16 for following procedure.
General
The main load drum (Drum 9) is equipped with a drum pawl
as shown in Figure 6-16. The drum is mounted in the boom
butt.
The pawl is a positive locking device which, when engaged,
prevents the drum from turning in the DOWN direction.
The drum pawl is engaged and disengaged electrically by a
motor driven screw-type actuator controlled by a switch in
the operator’s cab. A limit switch inside both ends of the
actuator turns off the motor when the actuator is fully
extended or retracted.
The drum pawl was adjusted at the factory and should not
need further adjustment during the service life of the
actuator. Adjustment is necessary when a new actuator is
installed.
Actuator Removal
1.
Toggle DRUM 9 PARK switch to OFF to disengage pawl
(4), and stop engine. Actuator will retract.
NOTE:
It may be necessary to hoist slightly before the
pawl will fully disengage.
2.
Disconnect electrical cord from actuator (5).
3.
Loosen jam nut (10) and back out adjusting screw (11)
until leaf spring (12) is fully relaxed.
4.
Carefully remove pin (7) securing actuator (6) to
bracket (8).
5.
If necessary, loosen bracket nuts (9) to loosen actuator
pin (7).
6.
Remove pin (5) to disconnect leaf spring (12) from
actuator (6).
7.
Remove actuator (6).
Actuator Installation and Adjustment
Actuator must be fully retracted during installation and
adjustment.
1.
Move cab power switch to ON position and engine run-
stop switch to RUN position. Do not start engine.
2.
Toggle DRUM 9 PARK switch to OFF to disengage pawl
(4).
3.
Connect electrical cord to actuator (6). Actuator will
retract.
4.
Insert pin (5) to connect leaf spring (12) to actuator (6).
5.
Pin actuator (6) to bracket (8).
6.
Set Dimension A (View A):
a.
Loosen bracket nuts (9).
b.
Adjust position of bracket (8) until dimension
between pawl (4) and ratchet tooth (3) equals
Dimension A.
c.
Securely tighten nuts (9) to hold bracket (8) in
position.
7.
Set Dimension B (View B):
a.
Loosen jam nut (10).
b.
Turn adjusting screw (11) IN until dimension
between pawl (4) and ratchet tooth (3) equals
Dimension B.
c.
Securely tighten jam nut (10) to lock adjusting screw
(11).
8.
Toggle DRUM 9 PARK switch to ON to engage pawl.
Actuator (6) will extend and pawl (4) will engage.
9.
Using park switch, operate pawl (4) to make sure that
internal limit switches stop actuator motor when actuator
(6) is fully extended and fully retracted and that pawl (4)
fully engages and disengages ratchet tooth (3).
WARNING
Flying Part Hazard!
Leaf spring is preloaded. Do not proceed to step 4 until
step 3 is performed. Parts will fly apart with sudden and
dangerous force if spring preload is not relieved.
WARNING
Pinch Point Hazard!
Actuator rod will retract when step 3 is performed, To
prevent crushing injury, keep hands away from actuator
and actuator clear of all other parts while performing step 3.
WARNING
Pinch Point Hazard!
Actuator rod will extend when step 8 is performed, To
prevent crushing injury, keep hands away from actuator
and pawl while performing step 8.
CAUTION
Actuator must be free to fully extend and retract. Motor will
overheat and be ruined if actuator stroke is restricted in
either direction.
