(16) Install plate (39), outer edge bevel facing up, on
back of air motor assembly (31). Shafts (37) fit into slots
on plate.
(17) Rack roller bearings (32) in accordance with
TM 9-214 and install (small end up) on bearing cone (34).
(18) Install main housing (51) over air motor assem-
bly (31). Ensure that shafts (37) are positioned correctly
and aline with relief holes in main housing.
(19) Carefully turn main housing (51) over, keeping
entire assembly tight to keep gears properly aligned.
(20) Install gear (30), ensuring that notches in gear
aline with side rod holes.
(21) Pack roller bearings (28) in accordance with
TM 9-214 and install (small end up) on bearing cone (46).
(22) Install grease fitting (33) in spacer cover (29).
(23) Install spacer cover (29) on main housing (51).
(24) Install cup (25) over roller bearing (28).
(25) Install retainer (26) and spring washer (27) on
cup (25). Ensure that dished face of spring washer faces
retainer.
(26) Install cover (24) on spacer cover (29).
(27) Lay drifter drill on its side and install two of the
side rods (11). Align internal parts then remove side rods.
Stand drill on front face.
(28) Install new seal (18) on main housing (51).
(29) Insert lower distributor (17) through seal (18)
and into main housing (51).
(16).
(30) If removed, install spring pin (23) in cylinder
(31) Install two new packings (21) in lower face of
cylinder (16).
(32) Install cylinder (16) on lower distributor (17).
(33) Install two new packings (20) in upper face of
cylinder (16).
(34) Install two new O-rings (19) in piston (15).
(35) Install piston (15) in cylinder (16), ensuring that
striking face is down.
(36) If removed, install spring pin (22) in upper dis-
tributor (12).
(37) Install upper distriiutor (12) over piston (15)
and into cylinder (16).
(38) Install muffler (14) and new seal (13). Install
muffler so that exhaust port will face slabback when drift-
er is installed.
(39) Install backhead (5) into upper distributor (12).
Install backhead so that port for blow hose elbow is on
same side as manifold (54).
(40) Install four side rods (11).
(41) Lay drifter drill on its side and install four nuts
(10). Tighten until snug.
(42) Install striker bar (3), bushing (2), and cap (1).
CAUTION
Side rod nuts must have the proper, equal torque
to pretension side rods and prevent the nuts from
working loose during use. Failure to apply proper
torque equally on all nuts could cause equipment
damage.
(43) Tighten side rod nuts (10) to 50-75 lb-ft.
NOTE
When drifter drill has been correctly assembled,
all parts will operate freely. To check assembly,
turn striker bar slowly by hand. It should revolve
uniformly. With proper preload on bearings,
striker bar can be rotated by hand, but with some
difficulty.
(44) Rotate striker bar (3) and ensure that all parts
turn freely, then tighten side rod nuts (10) to 100 lb-ft.
(45) Rotate striker bar (3) and ensure that all parts
turn freely, then tighten side rod nuts (10) to 150 lb-ft.
(46) Install flatwasher (7), new packing (8), and new
O-ring (9) on air tube (6).
(47) Install air tube (6) in drifter drill.
(48) Install gland plug (4).
(49) Install drifter drill (see TM 5-3820-241-12).
(50) Lubricate drifter drill (LO 5-3820-241-12).
Section II. LIFT AND SWING MECHANISM
7-4.
Feedshell Maintenance
(d)
Chain adjuster (see TM 5-3820-241-12).
a. Removal.
(e) Feed chain sprockets, bearings, and shafts
(1)
Remove the following components in the order
(see TM 5-3820-241-12).
listed:
(f)
Feed motor and gearbox assembly (see TM
(a)
Drifter drill (see TM 5-3820-241-12).
5-3820-241-12).
(b) Slabback (see TM 5-3820-241-12).
(g)
Centralizer (see TM 5-3820-241-12).
(c)
Feed chain (see paragraph 7-7).
(h) Foot (see TM 5-3820-241-12).
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