Tracked Equipment Steering Fundaments and Service Part B

Question 1

1.   List three (3) advantages that a hydrostatic steering system offers over a steering
clutch and brake system.
a)
b)
c)

Answer 1

1. a) Power is applied to both tracks when the tractor is being turned.
   b) Infinitely variable track speed and the ability to counter-rotate the machine makes the machine more maneuverable.
   c) Infinite speed control allows machine ground speed to be adjusted to provide optimum traction.

Question 2

2. The function of the flushing valve on a motor of a hydrostatic steering system is to:
   a) provide more efficient cooling for closed circuit components.
   b) control motor displacement.
   c) limit maximum pressure in the closed circuit.
   d) limit motor torque production.

Answer 2

2. a) provide more efficient cooling for closed circuit components.

Question 3

3. The ECU of an electronically controlled dual path hydrostatic steering system monitors machine tracking by:

Answer 3

3. The ECU of an electronically controlled dual path hydrostatic steering system monitors machine tracking by monitoring feedback signals from speed sensors mounted on the right and left track motors.

Question 4

4. The function of the speed sensor that monitors pump speed is to:

Answer 4

4. The function of the speed sensor that monitors pump speed is to provide the system ECU with a feedback signal proportional to engine speed. This signal allows the ECU to reduce machine speed when the engine rpm falls below the point where the engine can handle the load.

Question 5

5. The two (2) sources of input power to a steering differential are:
   a)
   b)

Answer 5

5. a) the powershift transmission.
   b) the hydraulic steering motor.

Question 6

6. The function of the steering motor on a machine equipped with a steering differential
   is to:
   a) determine machine speed and direction.
   b) provide machine braking.
   c) provide right and left turns.
   d) drive the powershift transmission.

Answer 6

6. c) provide right and left turns.

Question 7

7. When the steering motor is in the hold position on tracked equipment with steering
   differentials, the machine is performing:
   a) a gradual left tum.
   b) a gradual right tum.
   c) a counter rotation.
   d) straight movement.

Answer 7

7. d) straight movement.

Question 8

8. During counter rotation, the steering differential receives power from:
   a) the powershift transmission.
   b) the steering motor.
   c) both the powershift transmission and the steering motor.
   d) both the powershift transmission and the torque converter.

Answer 8

8. b) the steering motor.

Question 9

9. Machines that are equipped with a steering differential will stall the torque converter
   when sharp turns are made.
   a) true
   b) false

Answer 9

9. b) false; Machines that are equipped with a steering differential will stall the
   torque converter when the machine brakes are applied.