TOPIC 1. TRANSMISSION - TM-10-3930-644-14-P0090

TM 10-3930-644-14&P

TOPIC 1. TRANSMISSION

A. DESCRIPTION

TORQUE CONVERTER

The "Power-Shift" transmission consists of three major

The torque converter is composed of three members:

components: The torque converter, la hydraulically

The impeller or driving member, the turbine or driven

actuated clutch pack and a single speed, constant mesh

member, and the stator or reaction member.

The

transmission. A single lever type shift control is mounted

impeller forms the outer shell of the converter, and the

on the steering column to control the direction of travel

turbine and stator operate within the impeller but turn

through a control valve mounted on the transmission

free of the impeller. The impeller is mounted on the

housing.

engine flywheel and always turns at engine speed.

Power from the engine is delivered to the torque

The torque converter is filled with oil and when the

converter which, in turn, drives a pump and clutch pack.

impeller is rotated by the engine, the oil in the impeller

Housed in the clutch drum are two double faced clutch

vanes also rotates; and, being subjected to centrifugal

plates which, when activated, move the truck forward or

force, causes the oil to flow outward. At the beginning,

reverse through splined hubs, transmitting power to the

the turbine is stationary, and there is no centrifugal force

gear train.

on the oil in it. Therefore, the oil in the impeller, due to

its centrifugal force, enters the turbine near its outer

If the reverse clutch is activated, power is delivered to

circumference and forces oil from the turbine back into

the transmission through a hollow shaft which connects

the impeller near its inner circumference. A circulation of

the reverse gear and reverse clutch. If the forward

oil is set up, which continues as long as there is a

clutch is actuated, power is delivered to the transmission

difference between the speeds of the impeller and the

through a solid shaft, which rotates inside the hollow

turbine.

reverse shaft, connecting the forward gear and forward

clutch.

Figure 1-1. Power Shift Torque Converter Drive

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