Rear Axle - Overview (D.12.A - C.10.A.10) - Case IH AFX8010 Repair Manual

TRAVELLING - REAR AXLE

REAR AXLE - Overview (D.12.A - C.10.A.10)

AFX8010
The powered rear axle is available as a factory installed or field installed option. This system will provide additional
traction when the machine is operated in tough field conditions. The system can be engaged or disengaged
electronically by a switch in the operators cab. Both rear wheels are driven by hydraulic motors and the system
receives its oil supply directly from the hydrostatic pump. The high pressure lines from the hydrostatic pump (brake
manifold) supply the wheel motors through a control valve mounted near the rear axle. The powered rear axle
system operates as a function of the main hydrostatic drive system. A standard hydrostatic system utilizes one
pump and one drive motor (transmission mounted), whereas the powered rear axle system utilizes one pump and
three motors (one transmission mounted and two wheel mounted).The wheel motors are cam lobe type units with a
fixed displacement. The amount of wheel torque obtained from the wheel motors is directly related to the hydrostatic
system pressure. The higher the system pressure the greater the wheel torque will be.
NOTE: It is not necessary to synchronize the front wheels (transmission mounted pump driven) with the rear wheels
(wheel motor driven) as the system pressure and hydraulic fluid flow hydraulic will do this automatically.
It is very important to maintain traction to the front wheels. If a front wheel loses traction and begins to slip, the
system pressure will lower. The spinning wheel requires less pressure to rotate. The oil in the pressure lines will
take the least path of resistance, therefore the amount of power assistance from the rear wheels will be reduced
because of the lower pressure. Shifting to a higher gear (if possible) will reduce the amount of torque at the front
wheels to stop the wheel slippage. Also, lightly touching the brakes will help.
9687 1 27/05/2004
D.12.A / 4