7-3.
Drifter Drill Repair
(14) Remove bearing cup (25), retainer (26), and
spring washer (27) from front cover (24).
a. Disassembly.
(15) Remove bearings (28).
(1)
(16) Remove spacer cover (29), gear (30), air motor
assembly (31), and roller bearings (32). If air motor assem-
WARNING
bly is stuck, lay the drifter drill on its side and gently tap
Dry cleaning solvent P-D-680 is toxic and flam-
out the air motor assembly with striker bar (3).
mable. Wear protective gloves and use in a well
(17) Remove grease fitting (33) from spacer cover
ventilated area. Avoid contact with shin, eyes, and
(29).
clothes and do not breathe vapors. Do not use
near open flame or excessive heat. The flash
(18) Remove bearing cone (34) from carrier (35).
point is 100-138 degrees F (38-50 degrees C). If
(19) Remove two dowel pins (36), then remove car-
you become dizzy while using cleaning solvent,
rier (35).
get fresh air immediately and get medical aid. If
(20) Press two shafts (37) out of flange (38). Sepa-
contact with eyes is made, wash your eyes with
rate upper plate (39), flange (38), motor housing (40), two
water and get medical aid immediately.
bearings (41) and spacer (42), air motor gear (43), lower
plate (44), and two gears (45).
NOTE
(21) Remove bearing cone (46) from carrier (35).
Clean exterior of drifter drill before disassembly.
(22) Remove three gears (47) from shafts (48).
Use a babbitt hammer to drive off the heavier ex-
(23) Remove nut (49) from each shaft (48) and press
terior parts.
shafts out of carrier (35).
Handle parts carefully. Hardened parts might
(24) Remove bearing cup (50) from main housing
chip or break if dropped on a hard surface. Other
(51).
parts may be damaged by improper handling.
(25) Remove four screws (52) and lo&washers (53)
Clean disassembled parts in a solvent. Probe
securing manifold (54) to main housing (51). Remove
ports to loosen and remove foreign matter.
manifold and gasket (55). Discard gasket and lockwashers.
(26) Remove four screws (56) and lo&washers (57)
(2) Unscrew front cap (1) and remove bushing (2)
securing cover (58) to main housing (51). Remove cover
and striker bar (3).
and gasket (59). Discard gasket and lo&washers.
(3)
Remove gland plug (4) from backhead (5).
(27) Remove grease fitting (60) from main housing
(4) Remove air tube (6), washer (7), packing (8),
(51).
and O-ring (9). Discard packing and O-ring.
b. Inspection and Repair.
(5)
Remove four nuts (10) and side rods (11).
(1) Inspect all bushings, bearings, cups, and cones
(6) Lift off backhead (5) evenly and straight, being
in accordance with TM 9-214.
careful not to disturb upper distributor (12).
(2) If replacement is required, press two bearings
(7) Remove seal (13) and muffler (14). Discard
(61) and bushing (62) out of each gear (45) and replace.
seal.
(3) If replacement is required, press bushing (63)
out of each gear (47) and replace.
(8) Remove and separate upper distributor (12),
piston (15), cylinder (16), lower distributor (17), and lower
(4) Check striking face of piston (15). If wear is
greater than 0.030 in., grind striking face square. If wear
is greater than 0.050 in., replace piston.
(9)
Remove and discard two O-rings (19) from pis-
(5) Check clearance between piston head and cyl-
ton (15).
inder (16). If total clearance is greater than 0.015 in., re-
(10) Remove and discard two upper (20) and two
place piston, cylinder, or both.
lower (21) packings from cylinder (16).
(6) Check clearance between piston stems and up-
(11) If damaged, remove spring pin (22) from upper
per and lower distributors (12 and 17). If total clearance
distributor (12) and remove spring pin (23) from cylinder
is greater than 0.006 in., replace piston, distributors, or all
(16).
three parts.
(12) Turn drifter drill so that front cover (24) faces
(7) Check for gaulding and burning in the upper
up.
and lower distributors (12 and 17) and the cylinder (16).
Hone to clean or replace.
(13) Remove front cover (24).
7