Caterpillar final drive and transmission parts work together to transmit power to the ground and propel Cat earthmoving equipment through a variety of applications all over the world. Caterpillar designs and manufactures the highest quality drive train systems in the industry, achieving superior machine performance. Genuine Cat drive train parts, along with excellent maintenance and repair options, result in maximum productivity and lower owning and operating costs.

Drive train components must endure incredible torque, high impact loads, and frequent direction and gear changes. Caterpillar designs and manufactures its transmissions and final drive components with these demands in mind, using testing processes that simulate real world applications. The result is a drive train that lasts longer and works harder over the life of your machine.

The two primary components are, the Transmission which takes the output from the engine and manipulates it to control speed, direction, and torque; and the Final Drive, which reduces speed and increases torque.

Transmissions : The power coming from the engine must be turned into useful power by controlling its speed, direction and force. Transmissions do this by various means: hydraulically engaged planetary clutches and hydrostatic/ hydraulic drive. Each of these methods provides different characteristics of ground speed, torque, clutches maneuverability,and implement force.
ecause of the wide variety of work they do, Caterpillar products use several types of transmissions; each designed to convert engine power into the exact combination of speed and force required by individual machines.

Torque Converters/Dividers : The power that is produced in the engine is multiplied in the torque converter and then transferred on to the transmission for use by the rest of the drive train components.
Some CAT machines use a torque divider instead of the traditional torque converter, which divides the transmitted torque between the front and rear axles, with the rear receiving the majority.

Brakes : Brakes are the components that slow, stop or hold a machine stationary. On Caterpillar machines they are located at the wheels of wheel-type machines such as this off-highway mining truck. In track-type machines, they are located on the axle shafts.
Brakes usually work by pressing a non-rotating surface, such as a brake shoe, against a rotating surface, in this case, a brake drum. The resulting friction stops the machine. At this point where the two meet, the inertial force of the machine is sometimes converted into bake-oven heat.

Final Drive : The final drives are an important part of the drive train. They're the components that apply driving force to the wheels or tracks.
The final drives of a track-type tractor differ somewhat, but they perform the same function. They reduce rotating speed and increase torque. In fact, this is where the greatest torque rise occurs...in the gears.
That allows these components ahead of the final drives to be smaller, which saves weight and space.There are four types of final drives used in Caterpillar machines:

Differential : The differential will decrease the speed and increase the torque as needed for each wheel’s motion adjustment. When the machine is turning the differential will supply the needed adjustments to the wheels allowing the outside wheel to move at a faster pace than the inside wheel.
The final drives of a track-type tractor differ somewhat, but they perform the same function. They reduce rotating speed and increase torque. In fact, this is where the greatest torque rise occurs...in the gears.
That allows these components ahead of the final drives to be smaller, which saves weight and space.There are four types of final drives used in Caterpillar machines:

Drive Shaft : Drive Shaft is a means of connecting drive train components. It allows for misalignment in the drive. The output shaft connects to the transmission through a yoke and drive shaft or directly to the transmission input gear.
Caterpillar’s exact design for proper measurements and precise machining ensures proper gear alignment. Special heat treatment achieves proper surface hardness, core hardness, and hardened depth.