Binding of drive shafts and axles in part time 4WD systems, also called "axle wind up"






© 1997-2005 H. Pietschmann

How a need for more torque is handled by a 2WD and a 4WD

Task: A steep grade needs to be climbed and 220 units of torque are required to move the vehicle.


The 2WD vehicle utilizes only the traction of two tires which provide a total of 200 units of traction. They are "overpowered" by the 220 units of torque, resulting in two spinning tires. The 2WD vehicle cannot climb the grade.


The 4WD vehicle utilizes the traction of four tires which provide a total of 400 units of traction. They can easily handle 220 units of torque, with a safety of 180 traction units left(45 per wheel) . The 4WD vehicle climb the grade without slipping or sliding.

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