25
The 4WS system is for part-time operation only and is used to produce tight turns with the least crop damage,
when required.
The system may be selected at any time (while Field Mode is selected) by depressing the Foot Switch and
holding it depressed. However, the rear axle will not engage until the front axle is straight. This may be when
travelling straight in a tram line or when the front axle is being steered and passes through centre. When the
rear axle begins to move the 4WS Indicators on the Over Head Control Panel will illuminate. The 4WS
indicators remain illuminated when ever the rear axle is not aligned straight.
The Foot Switch may be released when the rear axle begins to steer, and the axle will continue to steer, until it
once again straightens up, at which point it will remain straight until the Switch is depressed again.
The operator should wait for the Air Pressure system to be fully charged (warning symbol on Electronic Dash
to be extinguished) before attempting to use the 4WS system.
In short, the rear axle will only engage when the front axle is straight, and will only disengage when it is itself
straight.
Two other 4WS modes are available - 4WS engaged with Spray OFF and 4WS Permanent.
4WS with Spray OFF engages the 4WS system without the use of the Foot Switch, when the Main Spray
ON/OFF is OFF (useful for when turning at headlands).
4WS Permanent engages the 4WS system all the time, without the use of the Foot Switch. Care must be taken
to disengage the 4WS system when it is no longer required.
As above, either of these modes will not engage unless the front axle is straight or disengage unless the rear
axle is straight.
Leakage within the steering system is corrected every time the rear axle disengages.
BEWARE: There are a number of situations in which 4WS should NOT be used. They are as follows:
1. On side slopes when any 'crabbing' will be amplified by the steering rear axle.
2. When turning on steep hills where the rear end inertia could turn the machine over.
3. In potato rows where the rear wheels will try and climb the balks.
4. On any field spraying where rear axle movement is amplified by the boom thus causing an
overlap/underlap situation at the boom tips.
5. Never engage 4WS at speeds over 15 km/h. 4WS can not be engaged while in Road Mode because not
only is it illegal, but is also extremely dangerous.
If the Air System fails, the machine will automatically revert to two-wheel steer, but the rear axle will remain at
the angle at which the air pressure was lost.
If the machine is parked with 4WS engaged, and air pressure is lost, the machine will 'crab', until air pressure is
re-instated and so the steering wheel should not turned until this has occurred.
Should the steering be turned to the extent that the rear wheels can no longer be straightened (due to air
pressure loss) the following operation will re-set the rear wheels
The rear wheels should be locked by pressing and holding the ‘4WS Permanent’ button for 5 seconds (it will
begin to flash). The front wheels should then be turned to a similar, opposite angle (as in 4WS).
Then press and hold the ‘4WS Permanent’ button again (until it stops flashing), the rear wheels may be turned
in conjunction with the front wheels back to the centre line where the system will re-align itself.
4 WHEEL STEER (4WS)
2.1-11
To Next Page
Loading...