Traction

Wheel slip occurs when power is routed to any one outer end of drive axles due to an extreme low coefficient of rolling resistance within the group.  This can be very frustrating to drivers, and very damaging to equipment once that spinning tire gains traction.

Tandem drive sets utilize an interaxle driveline to carry power from the forward to rear drive axles. Normal driving position is to have the interaxle lock disengaged. Tandem drive axle sets spin the outer ends independently, with power going equally to each of the 4 wheel ends… when the surface conditions have equal rolling resistance. If the traction changes for any one end, then the spider gears compensate (see previous article on spider gear function). The outcome of this can be described as one-wheel drive. At its most extreme, all the power can be flowing to one spinning outer end.

In low traction events a driver may lock the interaxle making certain that power goes to the rear axle, even if one outer end of the forward drive starts spinning. In this scenario, the vehicle has 2-wheel drive. The outer end opposite the spinning wheel could remain stationary, but one wheel on the forward drive and one wheel on the rear drive will turn. This is illustrated in the drawing above.

When application dictates these extreme conditions are part of the operation it is wise to consider differential locks. This product locks axles (forward, rear, or both) side to side, effectively transferring power to all the driving tires when locked in combination with the interaxle. If mud and snow, especially while operating off a well-maintained road, are expected this option is preferred over or in addition to standard Automatic Traction Control. Traction Control uses the Anti-lock Brake System to brake a spinning wheel, effectively transferring power on slippery well-maintained roads. The system is designed more to prohibit slippage as opposed to powering out of a bog.