TM 55-4920-227-15
(11) Install the bushing (12) and support arm (15)
secure the assembled varidrive to the frame
on the shaft (37) and secure with the nut
of the test stand.
(13) and retaining ring (9). Secure the
(7) Attach a sling to the three eyebolts and use
support arm (15) and shim (14) to the
a suitable lifting device to remove the
gearcase with two screws (10) and
assembled varidrive from the frame.
lockwashers (11).
(8) Remove four screws (10), lockwashers (9)
(12) Position the cover (5) and gaskets (6) on the
and remove the assembled adapter bracket
gear case and secure with four screws (7)
(56) and motor assembly (17) as a unit from
and lockwashers (8).
the case frame (20).
e. Installation and Adjustment.
(9) Remove three screws (40) and lockwashers
(1) Position the electric remote control (37, fig.
(41) that secure the bearing cap (58) to a
bearing boss inside the adapter bracket
with four screws (38) and lockwashers (39).
(56).
(2) Connect tagged electrical leads to proper
(10) Remove four screws (53) and lockwashers
terminals points.
(54) that secure the motor assembly (17) to
(3) Start the test stand (para. 20) and operate at
the adapter bracket (56). Remove the motor
11000 rpm. Center the high speed stop (16,
assembly from the adapter bracket and
simultaneously remove the assembled
the high speed stop with the screws (17 and
movable varidisc (19) from the shaft of the
18), until the stop contacts and trips the
motor.
microswitch (26).
(11) Remove the ball bearing (57) and bearing
(4) Decrease the speed to 1000 rpm, and adjust
cap (58) from the shaft of the motor
the low speed stop and microswitch (21) in a
assembly.
similar manner. Stop the test stand.
b. Disassembly.
(5) Position the gasket (2) and cover (1) on the
(1) Remove screw (42), washers (43 and 44)
gearcase (68) and secure with three screws
and pull the gear (45) from the control shaft
(3) and lockwashers (4).
(51). Remove the woodruff key (50) from
the shaft keyway.
(2) Remove four screws (46) that secure the
56. Adapter Bracket Assembly
a. Removal.
bearing collar (47) to the adapter bracket
(1) Remove the tube assembly (para. 42).
(56).
Rotate the control shaft (51)
(2) Tag and disconnect the tachometer
counterclockwise until free of the control nut
generator leads (para. 52).
(15). Remove the assembled varidisc (19)
(3) Remove the stationary motor varidisc (para.
and control shaft (51) from the adapter
bracket (56).
(4) Tag and disconnect the varidrive motor
(3) Press the bearing collar (47) from the ball
electrical leads (para. 57).
bearing (49). Remove the retainer ring (48),
(5) Remove four screws (38, fig. 18),
and press the ball bearing (49) from the
lockwashers (39) and remove the electric
control shaft (51).
remote control assembly (37) from the
(4) Remove screws (11 and 13) that secure the
assembled adapter bracket (56).
shifting lever (14) to the shifting bearing
(6) Remove four nuts (27), lockwashers (26),
housing (5) and remove the shifting lever
flat washers (25) and capscrews (24) that
from the housing.
AGO 6729A
34
