Table 7-1. Clutch Applications

TM 10-3930-633-34

impeller speed, the converter no longer multiplies

pressure against the clutch piston. The piston

torque. The fluid is directed against the back face

moves against a disc spring which acts as a lever

of the stator blades. As the one-way clutch

to lock the drive and driven plates together.

permits the stator to rotate only in the direction

When the clutch is applied, the primary sun gear

of impeller rotation, the stator begins to turn with

is locked to and driven by the turbine shaft. The

the impeller and turbine. The converter operates

piston is returned to the release position by the

as an efficient fluid coupling as long as the turbine

disc spring when the fluid pressure is removed. A

speed remains greater than 9/10 impeller speed.

check ball is installed in the front clutch piston to

permit fluid exhaust, when the piston is in its

(5) A constant flow of fluid into and out of

released position.

the converter is maintained. Some of the fluid

(2) In neutral, the front clutch drum and steel

coming out of the converter is forced through a

plates are being driven while the composition

cooler located in the radiator tank.

plates are stationary. In reverse, the clutch is not

b. Planetary Gear Train. The planetary gear

applied, since the steel and composition plates

train consists of a primary sun gear, secondary

must rotate in opposite directions. See table 7-1

sun gear, primary and secondary pinions which

for Clutch Applications.

are held in a common carrier, and an internal gear

d. Rear Clutch. The rear clutch is operated by

to which the transmission output shaft is at-

fluid pressure against the clutch piston.

tached.

Movement of the piston compresses the release

c. Front Clutch. The front clutch drive plates

spring and locks the multiple-disc clutch. The

are connected to the turbine shaft through the

rear clutch drive plates are splined to the front

front clutch drum. The driven plates are con-

clutch drum and the driven plates are connected

nected to the primary sun gear shaft.

to the rear clutch drum and secondary sun gear.

(1) The front clutch is operated by fluid

Table 7-1, Clutch Applications

Selector Lever

Clutch

Band

Gear

Position

Applied

Ratio

Neutral

. N . . . .. None... . N

one

.D..................

Front Front .

.1.47:1

. D . . . . . . . . . . . . .. Front and

Rear. . .. None.

.1.00:1

Reverse . . . . . . .

.R.

Rear. . .

...Rear . .2.00:1

(1) When the rear clutch is applied (in the

end of the band to tighten the band around the

reverse and third gear ratios) the secondary sun

rear clutch drum.

gear is driven. The piston is returned to the

(2) Under certain conditions, the servo is

released position by the release spring.

released by directing fluid pressure to the op -

(2) In neutral, the rear clutch composition

posite side of the piston, assisted by release

plates are being driven while the steel plates are

spring force.

free. In second gear, the composition plates are

f. Rear Band and Servo. The rear band fits

driven, but the steel plates are held stationary. In

around the planetary gear drum. One end of the

first gear, the composition plates are driven

band contacts the end of the band adjusting

clockwise at engine speed while the steel plates

screw, and the other end connects to the rear

are driven counterclockwise. See table 7-1 for

servo.

clutch applications.

7-3. Hydraulic Control System

e. Front Band and Servo. One end of the front

Operation of the servos and clutches is ac-

band, which encircles the rear clutch drum, is

complished by directing hydraulic fluid under

anchored to the transmission case, and the other

various pressures through the control valve body.

end is connected to the front servo.

The levels of these pressures are determined as

(1) Fluid pressure moves the front servo

outlined in the following paragraphs. Refer to

piston against the inner end of the front servo

figure 7-2 for a schematic of the hydraulic control

actuating lever. Force is transmitted through a

system.

strut between the outer end of the lever and the

7-2