accordance with current lubrication order (LO 53810-
(6) Tighten adjusting nuts fig. 4-1) on
20612), paying particular attention to dipper handle,
antisway springs to obtain spring tension, then hold
crowd chains, and crowd and reversing mechanism.
adjustment by tightening locknuts.
Protect all unpainted surface from rust or corrosion.
(7) Install revolving frame crowd chain on
(11) When removal is for purpose of installing
crowd reversing mechanism then on digging drum
crane front end attachment, remove shovel hoist cable
sprocket, and secure by installing master link (para 4-3),
then adjust (para 3-31). Install boom crowd chain on
and planetary pinion gear from digging drum (para 3-
reversing mechanism and sprocket on shipper shaft,
125); reposition planetary brake band (para 3-123), then
then adjust in a similar manner.
install crane lagging (para 3-124).
(8) Adjust dipper trip (para 3-33) and trip
cable (para 3-34).
4-3. Crowd and Retract Chain, Idler, and Tightener
(9) Perform preventive maintenance checks
and services (para 3-6), then raise boom (para 2-12b).
a. Crowd and Retract Chain Removal and
c. Removal.
Installation.
(1) Remove crane-shovel unit to storage
(1) Remove cotterpin, roller, and master pin
area, an area that is level, preferably hard surfaced,
from link of boom crowd and retract chain (fig.
under cover, suitable for storage of shovel front end
attachment.
foot of boom, chain tightener sprocket and shipper shaft
(2) Position two blocks, approximately 24 feet
sprocket.
from boom foot (fig. 4-1), then lower boom (para 2-12 b)
(2) Remove revolving frame crowd and
until dipper rests on blocks. Position blocking between
retract chain- from digging drum sprocket, idler roller,
dipper handle and boom point, then lower boom until
and crowd and reverse mechanism in manner similar to
point rests on blocking.
(1) above.
(3) Build a substantial crib under boom, near
(3) Install in reverse order of removal.
foot, until there is just room enough to insert wedges, or
jacks, to take weight of boom off boom foot pins.
b. Chain Tightener Adjustment.
Refer to
(4) Remove master pin of revolving frame
crowd chain and remove chain from shovel sprocket on
c. Idler Roller Adjustment.
Adjust in manner
digging drum. Reinstall master pin and position crowd
similar to that used for chain tightener (para 3-31).
chain back over boom crowd chain temporarily, until
cleaning and preserving is performed ((10) below).
4-4. Shovel Dipper
(5) Loosen locknut and adjusting nut from
antisway springs until all tension is removed from
a. Removal
springs.
(1) Lower dipper to rest on blocks, then
(6) Remove cable clamps from dead end
remove hoist cable from bail sheave only (fig.
sockets of dipper hoist cable and, boom hoist cable (fig.
(2) Refer to figure 4-4, disconnect trip chain
ends through sheaves as this is accomplished.
from trip lever, remove cotterpins from two pins
(7) Disconnect trip cable from lever
securing braces to dipper handle, then remove pins.
underneath revolving frame, remove from guide sheave
(3) Remove cotterpin and washer from two
at boom foot and secure it to boom and equalizer
handle pins, remove handle pins, then remove dipper
bracket.
from handle.
(8) Remove cotter pins from boom foot pins
b. Disassembly and Reassembly of Dipper.
(2), drive wedges between cribbing and boom foot until
(1) Remove cotterpin and bail pin (fig.4-4),
weight is off foot pins (or raise jacks), then remove
then remove bail.
boom foot pins.
(2) Remove bolt from chain at latch lever,
(9) Move crane-shovel unit away from shovel
then remove chain.
front end attachment.
(3) Remove cotterpin and pin from two
(10) When attachment is to be stored on
braces, then remove braces.
blocks for a prolonged period, clean with an approved
solvent, dry thoroughly, and lubricate attachment in
4-3
