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| Illustration 1 | g06200852 |
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Top view of the front differential (1) Bevel pinion shaft (2) Oil supply tube (3) Piston (4) Thrust Plate (5) Rotating plate (6) Friction disc (7) Differential Group (8) Axle shaft (9) Differential Bevel Gear (10) Differential case (11) Spider (12) Differential Gear (13) Differential Pinion Gear (14) Bevel Gear (15) Differential carrier | |
A differential divides the power that is sent to the machine wheels. During a turn, the inside wheel turns at a slower rate than the outside wheel. The differential still sends the same amount of torque to each wheel. Each differential has a differential lock. The main component of the differential lock is the clutch pack. When the differential lock control is energized by the chassis ECM, the clutch pack connects one axle shaft to the differential case. Both axle shafts are connected to form a solid axle with no differential effect.
The inside components of the differential receive lubrication from oil inside the axle housing.
Straight Forward or Straight Reverse Operation
When the machine moves in a straight direction with equal traction under each drive wheel, equal torque on each axle holds differential pinion gears (13) so the pinions do not turn on spider (11).
The universal joint for the rear axle or the front drive shaft for the front axle transmit drive to bevel pinion shaft (1). Bevel pinion shaft (1) turns bevel gear (14) and differential case (10). Differential case (10) turns spider (11). Spider (11) turns differential bevel gear (9) and differential gear (12) through differential pinion gears (13). Differential pinion gears (13) do not turn on spider (11). Differential bevel gear (9) and differential gear (12) turn axle shafts (8). The same amount of torque is sent to each wheel.
Forward or Reverse Turn Operation.
When the machine is turning, the outside wheel starts to rotate faster than the inside wheel.
Bevel pinion shaft (1) turns bevel gear (14) and differential case (10). Differential case (10) turns spider (11). Spider (11) turns differential bevel gear (9) and differential gear (12) through differential pinion gears (13). Because one side gear requires more force than the other side gear to turn, differential pinion gears (13) turn around the spider. As the pinions turn, the pinions move around the side gears, allowing the outside wheel to turn faster than the inside wheel.
The same amount of torque is sent to the inside wheels and to the outside wheels. This torque is only equal to the amount that is necessary to turn the outside wheel.
Loss of Traction (Wheel Slippage)
When one wheel has more traction than the other wheel, the differential operates in the same manner as if the machine is turning. The same amount of torque is sent to both wheels. This torque is only equal to the amount that is necessary to turn the wheel with the least resistance.
Differential Lock Operation
When the differential lock solenoid is energized, oil pressure is transmitted through oil supply tube on the front of the axle housing. Piston (3) is offset against thrust plate (4) which forces rotating plates (5) and friction discs (6) together, locking left axle shaft (8) to the hub assembly. This prevents differential bevel gear (9) from rotating inside differential case (10). Differential pinion gears (13) stop revolving and this causes differential gear (12) and right axle shaft (8) to lock. Both axle shafts now rotate at the same speed as the bevel gear and differential case.