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Technical reference page: 43

4WS setup procedure - rotary potentiometers

1) Check Tracking has been set - Front 0.5-2mm toe in - Rear 0.5-2mm toe out.

2) Check steering stops have been set to give 31° (max) steering angle. Adjust rams if necessary to utilise full ram travel.

3) Set front and rear wheels straight ahead. Use manual lever on Danfoss proportional valve to set rear wheels (after starting engine but before activating system). Use straight edges down both sides of machine, not forgetting to allow for toe in/out.

4) Clamp markers to springs and mark track rods to indicate central positions of both axles.

5) Set all four potentiometers on Danfoss control box to mid-way position.

6) Activate system with engine running and with front wheels set in central position. Set control to 2WS

7) Connect voltmeter to purple test wire from bottom of control box (Terminal 16). Check and record voltage (should be approx 5.5 - 6v)

8) Switch to 4ws & slacken bottom grub screw on front potentiometer drive coupling. Rotate coupling untill you get the same voltage reading as in 7) above, then doublecheck by switching back to 2ws. Tighten grub-screw when both readings are exactly the same.

9) Set to 4WS and ensure the front wheels are in the central position. Slacken the bottom grub screw on the rear potentiometer drive coupling taking care not to stand inbetween the wheel and the chassis. Rotate the coupling untill the rear wheels are straight with the mark on the track rod lined up with the pointer.

10) To check adjustment switch from 2WS to 4WS and to crab and back again with the front wheels in the central position and, if correctly set, the rear wheels should not move.

11) Turn pot 4 anticlockwise to slow response back down. Set it so there is no "jerkiness" when steering. Be careful - it is a very fine adjustment. Once set you will find if you turn into full lock and then switch to 2WS, the rear axle, when centralising, will stop just short of the central position. This is quite normal and will not be noticable in the field. It is possible to set the response to return it to the exact centre position, however if you do this the system will "hunt" and become very jerky. About 1mm (on the track rod) short of the central position will probably be about the right compromise.

12) Check to see if rear wheels are turning through the same steering angle as the front wheels.
  If the rear wheels turn sharper than the front wheels turn pot 1 anti-clockwise
  If the front wheels turn sharper than the rear wheels turn pot 2 ant-clockwise