man on each side of boom to help guide dipper handle
(4) Remove two bolt and nut from latch lever,
into saddle blocks.
remove latch lever, then remove clevis and latch bar
from dipper door.
(4) Pull hoist cable in slowly and move lifting
device forward.
(5) Remove cotterpin from two door hinge
pins, remove pins, then remove dipper door.
(5) Guide dipper handle into saddle blocks,
making sure that racks engage with pinions on shipper
(6) When necessary to remove latch keeper
shaft.
for repair or replacement, remove two short and four
long rivets then remove keeper.
(6) Install boom crowd chain over sprocket on
shipper shaft and crowd and reversing mechanism at
(7) Disassemble bail (para 4-6).
foot of boom and secure with master pin, roller, and
(8) Reassemble in reverse order of
cotter pin (para 4-3).
disassembly.
(7) Install dipper trip cable on dipper handle
c. Cleaning, Inspection, and Repair.
(1) Clean all parts with an approved cleaning
(8) Install shovel dipper (para 4-4).
solvent and dry thoroughly.
(2) Visually inspect all parts for signs of
4-6. Dipper Bail and Sheave
excessive wear, cracks, breaks, bends, stripped threads
on hardware, or elongation of holes.
a. Removal.
(3) Repair by welding cracks or breaks,
straightening bends and replacing all defective hardware
(1) Remove shovel dipper (para 4-4).
or excessively worn parts.
(2) Remove bail (para 4-4b(1)).
d. Installation.
b. Disassembly and Reassembly.
(1) Position dipper at end of dipper handle,
(1) Remove cotterpin and slotted nut from
install two handle pins and secure each with washer and
sheave pin.
cotterpin.
(2) Remove sheave pin, then remove sheave
(2) Place two braces at lugs on dipper
from bail.
handle, install pins and secure with cotterpins.
(3) Reassemble by reversing steps (1) and
(3) Connect door trip chain to trip lever, then
(2) above.
reeve hoist cable (fig. 2-19).
c. Cleaning and Inspection.
4-5. Dipper Handle
(1) Clean all parts in an approved cleaning
a. Removal.
solvent and dry thoroughly.
(1) Open boom crowd chain by removing
(2) Visually inspect sheave for scored sleeve
cotterpin, roller, and master pin, then lifting chain off
bearing, cracks, worn groove, or other defect. Inspect
sprocket on shipper shaft.
bail for cracks, breaks, elongated mounting holes, or
(2) Remove shovel bucket (para 4-4).
defective mounting hardware. Replace all defective
parts.
(3) Remove dipper trip cable from dipper
handle (para 4-8).
d. Installation.
(4) Lash saddle blocks to boom so that they
(1) Install bail on dipper (para 4-4b).
are prevented from changing angles when dipper handle
(2) Install shovel dipper (para 4-4d).
is removed from shipper shaft.
(5) Fasten one end of a heavy rope about
47.
Dipper Teeth
three feet from dipper end of handle, the other end of
rope to boom point of lifting device. Move dipper
Caution:
handle until pointed end is almost at shipper shaft, and
Never dig with shovel front end
almost free of saddle blocks.
attachment while a tooth is missing
(6) Lower dipper end, if necessary, then work
from dipper, even for a short time.
points of handle over pinions, carefully, and lower dipper
The tooth socket will wear to such an
handle to ground.
extent that a replacement tooth will
b. Installation.
never fit properly. Reinstall old worn
(1) Position shovel boom to receive dipper
tooth and use until new one is
handle, making sure saddle blocks are lashed secure to
available, when continued operation
boom.
is imperative.
(2) Position lifting device, and clamp hoist
a. Tooth Removal.
cable -round dipper handle at balance point (about three
(1) Lower dipper to rest on blocking or
feet from dipper end).
(3) Lash a heavy rope to point end of handle,
thread it through, or over shipper shaft, then station one
4-5
