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| Illustration 1 | g00274836 |
(1) Torque control lever | |
When the all wheel drive control is turned to the MANUAL position or turned to the AUTOMATIC position, power is provided by the hydraulic system to the front wheels. When the all wheel drive control is in the MANUAL position, the hydraulic system attempts to keep the pump pressure at a constant value.
In the MANUAL position, torque control lever (1) allows the operator to adjust system pressure. Torque control lever (1) controls the front wheel torque. The operator can adjust torque control lever (1) . Adjusting torque control lever (1) will vary the front wheel torque. This will allow the operator to match the operating conditions.
When the torque control lever is pulled all the way to the back, a minimum pressure of 5500 kPa (800 psi) is created. In this position, minimum front wheel torque is generated. When the torque control lever is pushed all the way to the front, a maximum pressure of 35000 kPa (5080 psi) is created. In this position, maximum front wheel torque is generated.
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| Illustration 2 | g00274601 |
All wheel drive pump pressure versus the position of the torque control level. (Refer to table 1 below.) (2) Maximum pressure (3) Maximum pressure in Seventh gear (X) Percent of torque control (Y) Pump pressure | |
| Y Axis | Pump Pressure |
| A | 0 kPa (0 psi) |
| B | 10000 kPa (1450 psi) |
| C | 20000 kPa (3000 psi) |
| D | 30000 kPa (4350 psi) |
| E | 40000 kPa (5800 psi) |
In the AUTOMATIC position, the amount of torque at the front wheels is determined by two factors. The slip ratio of the rear wheels and the position of torque control lever (1) . See Illustration 2 and Table 1 above. The slip ratio is the difference between the speed of the rear wheels and the true ground speed divided by the speed of the rear wheels. The true ground speed is sensed by ground speed sensor (4) . Ground speed sensor (4) is mounted underneath the operator's compartment.
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| Illustration 3 | g00274602 |
(4) Ground speed sensor | |
As the slip ratio increases the all wheel drive system pressure will increase. This will produce greater front wheel torque. As the slip ratio decreases the opposite effect takes place.
Torque control lever (1) is used to vary the relationship of the slip ratio to the system pressure. The operator controls the sensitivity of the front wheels by adjusting the torque control lever. The position of the torque control lever will determine the amount of time in order to increase the torque to the front wheels. The all wheel drive system will respond faster when the torque control lever is in the forward position. Controlling the torque control lever during the operation will make the all wheel drive system more powerful or less powerful, as traction conditions change.