824 TRACTOR Driving The Tractor Caterpillar

Driving The Tractor

------ WARNING! ------

Do not operate the machine until the proper brake oil pressure has been reached. See the preceding topic for proper brake oil pressure.


The tractor is equipped with a power shift transmission having three speeds in forward or reverse and is controlled by the selector lever mounted at the left of the steering column. The lever, when moved actuates a hydraulic control which directs oil into the chambers of the various clutches, of which there are five, thus producing the desired speed and direction of travel.

Two of the five clutches control direction of travel and are called directional clutches, one clutch controlling forward direction, the other reverse.

Three clutches control the speed in either direction and are called speed clutches. Shifting from one speed to another while traveling in either direction can be accomplished with the diesel engine running at any speed and while operating under light or heavy load conditions. Normally the accelerator would be released to reduce engine speed when making a directional change but it is permissible to make directional changes in first or second speed range at full engine speed. Detents within the transmission hold the control lever in the desired position.

Governor Hand Control: On compactors, positioning the governor hand control will maintain a constant engine speed. The foot pedal, however, will override the setting of the hand control for acceleration or deceleration. After releasing the foot pedal, the pedal returns to the speed setting of the hand control.

Shifting the Transmission: A safety lock is provided to hold the range selector lever in the neutral position when the machine is stopped. To lock, raise the handle. To unlock, move the handle down.

An interlock mechanism is also provided between the transmission control and the parking brake control. The parking brake must be released before the range selector lever can be moved to an engaged position.

If the engine is started when the range selector lever is in any position other than neutral, it will be necessary to move the selector lever to neutral position before the machine can be driven.


The safety lock and parking brake should be applied whenever the tractor is allowed to stand with the engine running. These safety devices prevent accidental engagement of the transmission.

The transmission selector lever positions are shown here and appear on the control housing.


Before applying any load allow the diesel engine to warm by running the engine five minutes with the accelerator in half engine speed position. During the warming period the power shift transmission selector control lever should be in neutral (N) position.


Before driving the tractor after transmission oil drain and fill periods, the transmission lubricating oil system should be completely filled. To do this, start the diesel engine and run it at half engine speed for 2 minutes. Recheck transmission oil level gauge and add oil if necessary.

To drive the tractor, proceed as follows:

1. After the engine warm-up period, release the accelerator to the low idle position.
2. Release the safety lock and parking brake and move the selector lever to the desired speed and direction position.
3. Depress the accelerator to attain the desired speed.

This machine is equipped with a reversible fan which provides either a suction or blower fan arrangement. As a blower fan the air flow is directed away from the operator's compartment.

As a suction fan, the air flow is directed around the diesel engine towards the operator's compartment. See the topic, REVERSIBLE FAN, for more information.


When moving downhill, do not shift the range selector lever to the opposite travel position for retarding purposes. Operate downhill in low gear speed range and use the right brake pedal to prevent the machine from traveling faster than the normal maximum for the gear speed selected. Operate at approximately half engine speed to provide adequate oil supply to the steering and brakes.

Steering: Steering is accomplished by the action of the hydraulic steering cylinder pushing the front frame to the right or left in relationship to the rear frame of the unit. The control of the pressure is obtained through the hydraulic control valve which is actuated by turning the steering wheel. If a gradual increase in the turning angle is desired, the operator must continue to turn the steering wheel. As soon as the operator stops turning the steering wheel, the follow up mechanism returns the control valve to the neutral position and the machine will continue to turn in that same radius until the steering wheel is again turned. For additional information see the topic, HYDRAULIC STEERING SYSTEM.