drums, guiding ends through sheaves as this is
Note. When removal of shovel front is for
purpose of installing any attachment except shovel
(7) Disconnect trip cable from lever
front, do not install planetary pinion gears.
underneath revolving frame, remove from guide
sheaves at boom foot and secure it to boom and
4-3. Crowd and Retract Chain, Idler, and Tightener
(8) Remove cotter pins from boom foot pins
a. Crowd and Retract Chain Removal and
(2), drive wedges between cribbing and boom foot until
weight is off foot pins (or raise jacks), then remove
(1) Remove cotterpin, roller, and master pin
boom foot pins.
from link of boom crowd and retract chain (fig.
(9) Move crane-shovel unit away from shovel
4-3), then lift chain off crowd and reverse mechanism
front end attachment.
foot of boom, chain tightener sprocket, and shipper shaft
(10) When attachment is to be stored on
blocks for a prolonged period, clean with an approved
(2) Remove revolving frame crowd and
solvent, dry thoroughly, and lubricate attachment in
retract chain from digging drum sprocket, idler roller,
accordance with current lubrication order. (LO 5-3810-
and crowd and reverse mechanism in manner similar to
301-12), paying particular attention to dipper handle,
crowd chains, and crowd and reversing mechanism.
(3) Install in reverse order of removal.
Protect all unpainted surfaces from rust or corrosion.
b. Chain Tightener Adjustment.
(11) When removal is for purpose of installing
crane front end attachment, remove shovel hoist cable
c. Roller Adjustment. Adjust in manner similar to
and planetary pinion gear from digging drum (para 3-
Figure 4-4. Shovel dipper, removal, disassembly, reassembly, and installation.