Chapter 7 REPAIR OF TRANSMISSION ASSEMBLY

TM 10-3930-633-34

CHAPTER 7

R E P A I R OF TRANSMISSION ASSEMBLY

Section 1. DESCRIPTION

7-1. General

b. The transmission consists essentially of a

torque converter, planetary gear train, two

a. The transmission is a two speed unit capable

multiple disc clutches and a hydraulic control

of providing automatic upshifts and downshifts

system. Figure 7-1 shows all the components of

through the two forward gear ratios, and also

the transmission.

capable of providing manual selection of first and

second gears.

Figure 7-1. Transmission Cutaway.

7-2. Operation

(2) The converter torque multiplication

gradually tapers off as turbine speed approaches

a. Torque Converter. The hydraulic torque

impeller speed, and it becomes 1 to 1 when the

converter consists of an impeller (pump), a

turbine is being driven at 9/10 impeller speed.

turbine, and a stator. AU these parts are enclosed

This is known as the coupling point.

and operate in a fluid-filled housing.

(3) When the turbine is rotating at less than

(1) When the engine is running, the fluid in

9/10 impeller speed, the converter is multiplying

the torque converter flows from the impeller to

torque. The fluid leaving the turbine blades

the turbine and back to the impeller through the

strikes the front face of the stator blades. These

stator. This flow produces a maximum torque

blades are held stationary by the action of a one-

increase of about 2 to 1 when the turbine is

way clutch as long as the fluid is directed against

stalled. When enough torque is developed by the

the front face of the blades.

impeller, the turbine begins to rotate, turning the

(4) When the turbine rotates faster than 9/10

turbine shaft.

7-1