TM 5-2420-230-24-1
Maintenance & Service Manual
R & HR32000 3 & 6 Speed LD
TRANSMISSION ASSEMBLY
The transmission and hydraulic torque portion of the power train enacts an important role in transmitting engine power to the driving
wheels. In order to properly maintain and service these units it is important to first understand their function and how they operate.
The transmission and torque converter function together and operate through a common hydraulic system. It is necessary to consider
both units in the study of their function and operation.
To supplement the text below and for reference use therewith, the following illustrations are provided:
Basic Design Silhouette
Converter Group
Converter and Transmission Case Group
Reverse and 3rd, Forward and 2nd Clutch Group
Low (1st) Clutch and Output Group
Regulating Valve, Charging Pump and Filter Group
Control Valve Assembly
Axle Disconnect and Mechanical Parking Brake
Assembly Instruction
Ring Gear Installation
Clutch and Gear Arrangement
Three Speed Power Flow
External Plumbing
The R, HR, and MHR Model Transmissions are of three basic designs.
The R Model consists of a separate torque converter, mounted to the engine with the powershift transmission remotely mounted and
connected to the torque converter with a drive shaft.
The HR Model consists of a torque converter and powershifted transmission in one package mounted directly to the engine.
The MHR version is a mid-mount torque converter and transmission assembly connected to the engine by means of a drive shaft,
(See Fig. A for basic design silhouette,)
The shift control valve assembly may be mounted directly on the side of the converter housing or front transmission cover, or remote
mounted and connected to the transmission by means of flexible hoses. The function of the control valve assembly is to direct oil
under pressure to the desired directional and speed clutch, A provision is made on certain models to neutralize the transmission when
the brakes are applied. This is accomplished through use of a brake actuated shutoff valve. The speed and direction clutch assem-
blies are mounted inside the transmission case and are connected to the output shaft of the converter either by direct gearing or drive
shaft. The purpose of the speed or directional clutches is to direct the power flow through the gear train to provide the desired speed
range and direction.
An axle disconnect is optional and is located on the output shaft, The drive to the front or rear axle can be disconnected or connected
by manual shifting.
F-26
