The M113A3 personnel carrier has an Allison X200-4 Hydromechanical
Cross Drive Transmission.
The transmission has a hydrostatic
steering system, its own oil system and filters (separate from the
engine), and a separately mounted oil cooler. It uses constant mesh,
spur type, and planetary gearing and has four forward ranges and one
The transmission also incorporates an infinitely
variable, hydrostatically controlled, differential steering system
and hydraulically controlled, multiple wet plate braking system. The
transmission couples to the rear of engine, at the flywheel end, and
receives engine power via the torque converter. Through its design,
the X200-4 transmission will NOT change direction (forward or
reverse) when the vehicle is moving at speeds above four miles per
This prevents damage to the transmission if the operator
accidentally changes the transmission controller to a reverse or a
forward range when the APC is moving. The X200-4 transmission has an
The A2 configuration of the APC has an Allison TX 100-1 transmission.
This transmission is a powershift, torque converter, planetary gear
This transmission consists of a compact unit which
mounts on the vehicle's engine to form a power pack.
In the A2
configuration, the transfer gear case and torque converter transfers
engine power to the transmission.
From the transmission, power is
then transferred to the differential and on to the final drives. The
TX 100-1 transmission has a net input of 215 horsepower at 3825 rpm.
The steering and braking for the A3 configuration is controlled
through linkages connected to the X200-4 transmission while the
steering and braking for the A2 configuration is controlled through
the steering control differential. The use of the X200-4 cross drive
transmission eliminates the use of the transfer gear case, the TX100-
1 transmission, and the steering control differential.
provides an illustration of the X200-4 transmission and figure 1-12
illustrates the TX 100-1 transmission.