34. ARSC (AUTOMATIC RETARD SPEED CONTROL) 34.2.5 METHOD OF DECREASING SET SPEED If it is desired to decrease the set speed, operate the retarder control lever to reduce speed, and when the desired set travel speed is reached, press the set switch on the ARSC set lever. The set travel speed will be changed to the new speed. REMARK After using the retarder control lever to reduce the speed, return it to its original position. 34.2.6 TRAVELING AGAIN AT SET SPEED If the machine repeatedly travels on the same slope, once the travel speed has been set, it is possible to operate the ARSC without carrying out the setting operation each time.
Before entering a downhill slope, if the travel speed has been adjusted to a speed lower than the set speed displayed on the travel speed display, the READY lamp (green) lights and the ARSC is actuated when the accelerator pedal is released. REMARK When traveling at a speed greater than the set speed displayed on the travel speed display, the ARSC is not actuated even when the accelerator pedal is released. When this happens, the READY lamp (green) also does not light up. Always adjust the travel speed to a speed lower than the set speed displayed on the travel speed display, and check that the READY lamp lights up. 34.2.7 METHOD OF CANCELING SET TRAVEL Method 1:
If the cancel switch is operated for more than 1 second, the control is stopped. When this happens, the travel speed display shows 0. Method 2: If the system switch is turned OFF, the control is canceled. When this happens, the travel speed display goes out. REMARK The switch must be operated for at least 1 second (different from other switches) to cancel the control. This is to prevent any problem of the control being canceled if the switch is touched by mistake. 34.2.8 RELATIONSHIP WITH EXHAUST BRAKE If the exhaust brake switch is at ( k ) position (ON), the exhaust brake is actuated in the normal way when the accelerator pedal is released if the torque converter lock- up is ON.
If the machine attempts to travel at a speed greater than the set speed, the ARSC is actuated. If the exhaust brake switch is at ( i ) position (OFF), the exhaust brake is not actuated when the ARSC is being operated. If the foot brake or retarder control lever are operated, the exhaust brake is actuated in the same way as normal. If the downhill slope is not steep and the engine brake and exhaust brake have ample effect, the machine will not accelerate to the set travel speed, so the ARSC may not be actuated. 34.2.9 RECOMMENDED SET SPEED Set the travel speed so that the engine speed is at least 1800 rpm, and travel so that the retarder oil temperature gauge is in the green range.
34.2.10 OVERHEAT WARNING If there is danger that the retarder oil may overheat, the ARSC caution lamp lights up and the set travel speed is automatically reduced approx. 1 km/h (0.6 MPH) every 3 seconds. The lower value for the set travel speed when the speed is automatically reduced is 10 km/h (6 MPH). 5-45