TM 9-2350-247-20-1
THEORY OF OPERATION — Continued
0003 00
DIFFERENTIAL COMPONENTS (M548A1)
The differential consists of three major assemblies. These are the right angle gearbox, steering unit with brake shoes, and two
output shafts.
Power flows from the transmission to the right angle gearbox to the steering unit. When driving straight forward, the steering
unit delivers equal power to both output shafts. Pressure on either right or left steering lever slows or stops the right or left
brake drum inside the center steering unit and reduces the speed of the right or left output shaft. By slowing down one side,
the differential action within the steering until increases the speed of the opposite output shaft and causes the carrier to turn in
the direction of the applied brake. Pulling with equal pressure, exerted at the same time on both right and left steering levers,
applies both brakes and slows or stops the carrier.
Differential is protected from high oil temperatures by a differential overheat switch connected to a warning light in the
driver’s compartment. The warning light comes on when the oil temperature is too high.
The breather needs to be kept clean and free of oil and dirt. If the breather is plugged, the oil inside the differential will build
up pressure and low out a gasket, preformed packing, hose, oil level gauge rod.
The resilient mount reduces shocks to the differential housing. Two lifting eyes are provided for removal and installation of
the differential from the carrier.
0003 00-12
