TM 5-3820-239-15
Section XII. COMPLETE TRACTION DRIVE
(6) Remove screws (22), nuts (23), lock
washers (24) and brake cylinder
This section contains repair instructions for
cover (25), with setscrew (20) and
the complete traction drive. The pneumatic
jam nut (21) attached.
drill contains two complete traction drives (one
(7) Insert two 5/8-11 threaded bolts into
for each traction unit), which are identical
the holes in the tip of brake piston
except for orientation, and quantities specified
(27), and pull out the piston and
throughout this section are for one traction
O-ring (28).
drive.
(8) Loosen jam nut (30) and turn brake
shaft setscrew (29) to release pres-
6-79. Removal
sure on the trunnion of brake band
Remove the complete traction drive as de-
assembly (39).
(9) Remove brake band anchor pin (31).
(10) Remove bolt (32), with brake spring
washer (33) and brake spring (34).
6-80. Disassembly
(11) R e m o v e b r a k e c y l i n d e r ( 3 7 ) a n d
a. Complete Traction Drive. Disassemble
brake cylinder case gasket (38).
complete traction drive in the numerical se-
(12) Remove brake band assembly (39)
from the housing.
following special procedures:
(13) Using retaining ring pliers; remove
(1) After draining the hydraulic oil by
retaining ring (40), and pull drive
removing magnetic plug (1, fig. 6-
shaft (42), with or without motor
28) and pipe plugs in bottom of gear
pinion ball bearing (41) attached,
housing (53) and propelling air mo-
out of gear housing (53). If the bear-
tor (10), remove screws (7), nuts
ing is installed in the shaft, pull it
(8), and lock washers (9), and care-
out of the recess in the drive shaft
fully pull the propelling air motor off
with an internal bearing puller.
the shaft of motor pinion gear (12).
(14) If necessary for replacement, remove
(2) Remove casing cover (14). Remove
retaining ring (43) and press drive
and discard both motor case gaskets
shaft ball bearing (44) out of the
bore in gear housing (53), using a
(13).
(3) Remove motor pinion gear spacer
bearing pusher to bear on the outer
(11) and pull out motor pinion gear
race of the bearing.
(12). If motor pinion ball bearing
(15) Drive out roll pin (45) and remove
(41) comes out with the gear, remove
clutch lock pin handle (46).
the bearing using a suitable bearing
(16) Drive out roll pin (47) and unscrew
puller to bear on the inner race only.
clutch spring cap (48). Remove re-
(4) Using retaining ring pliers, remove
maining parts.
retaining rings (15), and pull the
b. Propelling Air Motor. Disassemble pro-
assembled planet gears (18), ball
pelling air motor in the numerical sequence as
(16) off the stubs of drive shaft (42).
special procedures:
ted into the planet gears, and should not
and cylinder gasket (13).
be removed unless replacement is required.
(2) Rotate crank assembly (25) until the
piston (18) from which the cylinder
(5) Pull on clutch lock pin handle (46),
was removed is at top dead center.
and twist to lock it in the disengaged
Remove wrist pin caps (14) wrist pin
position. Remove internal gear (19).