Axle Info

Axle Camber

The angular relationship of the wheel to the road surface in the vertical plane.  Axles are typically built with a pre-determined bend in the tube that compensates for the expected deflection under load.  Ideally, the tire footprint will contact the road evenly across the width of the tread.

 

 

 

Hanger Installation
Most hangers are channel shaped steel stampings, designed to be welded to the underside of the frame rails to provide the attaching points for the leaf springs and their associated parts.  The attaching parts are normally  provided in kits, which contain all the necessary hardware to properly install the running gear.  In the case of multiple axle installations, equalizers are often used to help transfer load from one axle to the other(s) as the trailer moves over uneven terrain.  Not all combinations of equalizers are suitable.  If the  equalizer hangers are too short, the spring eye may contact the frame during articulation of the suspension and result in overloading of the spring.

Over tightening the nuts can lead to fastener failure.  The torque specification for the 7/16" - 20 Hex nut used on shouldered shackle bolts is 30 - 50 lb. ft.

The nut should not be used to "pull" the shackle bolt into the hanger.  Instead, the bolt should be driven into place to allow the serrations to grip the hanger.

Using an impact wrench without some type of torque limiting device can damage the threads and the serrations.

Shackle bolts that are free to rotate will severely limit the service life of the hangers.

 

Dimensional Requirements
Where to locate the axle set on trailer frame.
  1. Measure the distance from the center of the hitch to the center of gravity (dim A).
  2. Divide this value by the percentage of the load to be carried by the running gear.
  3. The result will be the distance from the center of the hitch back to the center of the axle
    set (dim B).

Note: "Center of Axle Set" on a Torflex axle is defined as the center of spindle.

 

 

 

Spring Suspension Comparison

Double Eye Springs Slipper Springs

Pros Cons Pros Cons
  • Smoother and quieter than slipper springs
  • Better weight distribution
  • Cheaper

 

 

  • More moving parts, more bushings to wear
  • Small bushing diameter, which means a shorter lifespan
  • Limited weight capacity - Max 3000 lbs. springs, good for up to a 6K Axle.
  • Less moving parts, less bushings to wear
  • High quality and larger bushings in eyes
  • Higher capacity options available - up to 7,500 lb. springs, good for up to a 15K Axle
  • Noisy due to the metal on metal rear of spring meets with equalizer/rear hanger
  • Weight distribution not as effective between axles.