Field Repairs of Tractors and Trailers for the Driver/Sliding Axles & Slider Repair

= Sliding Axles & Slider Repair =

First presented are techniques for sliding trailer tandem axles under normal circumstances, second are techniques when normal techniques don't work, third are field repairs that can be made.

Calculating weight redistribution, legal weight limits are not discussed in this chapter.

The reasons one might want to slide the trailer axles are:
 * to balance the weight of the rig for operational or legal requirements. Operationally it is best to have nearly equal weight on the drive axles and the trailer axles.  This makes braking and control easier.  If too much of the weight is carried by the trailer, the drive axles will not adhere to the road properly.  This can result in the drives being lifted off the road surface and loss of control.
 * to meet king pin to axle requirements
 * to aid maneuvering (typically all the way back for docking in a tight space or all the way forward for making tight road turns)
 * as a safety precaution for unloading (this is to prevent forklifts from causing the tail to drop, which is especially important if the tractor is not present to act as a counter weight)

Standard Techniques for sliding trailer tandem axles
The optimal way to slide trailer axles depends on the equipment available and if a helper is available. The following will be described:
 * without help
 * trailer brake available
 * trailer brake not available
 * with help
 * trailer brake available
 * trailer brake not available

Without help and trailer brake available
Some tractors have the ability to apply the service brakes on the trailer separately from the tractor brakes. The trailer service brake is always preferred as it applies more brake power than the spring brakes that are activated by the trailer brake button found on all tractors.


 * 1) stop the rig
 * 2) set only the tractor parking brake (you may need to hold the trailer button in while pulling the tractor button)
 * 3) make sure the transmission is in neutral
 * 4) alight from the tractor
 * 5) disengage the slider pins (the techniques for doing this on the various types of mechanisms is treated bellow)