How To Select Tubular Axles & Running Gear

A: The total Gross Vehicle Weight of the trailer to be built must be determined in order to select the axle or axles to properly fit the application. GVW is the Gross Vehicle Weight including the weight of the empty trailer and the weight of the intended cargo. (Example: GVW of 10.000 Ibs. = 2.000 lb. empty trailer weight + 8.000 Ibs. cargo.)

A: After GVW is known, you must select the number and capacity of the axles. For example, if you want 10,000 lb. GVW and want tandem axles, the minimum required capacity is 6,000 lb. per axle.

A: Determine if you want brakes on each axle. Most provinces require by law that one axle has brakes. Some provinces require that all axles have brakes. To determine how many brakes are necessary in a province, contact the local Department of Motor Vehicles. What type of brake do you prefer: Electric, Hydraulic Single-Serve, Hydraulic Free-Backing, Hydraulic Duo-Serve, Hydraulic Disc or Air “S” Cam Brakes?

A:

1. Is the trailer you are outfitting going to be a Bumper Pull, Gooseneck, King Pin or Pintle Eye Type?
2. Is the trailer going to be a flat bed with the bed above or between the tires?
3. Is the trailer going to need to be built with a low ground clearance? With an extra wide bed?

A: Straight spindles are used mostly when the bed is over the tires or when low ground clearance is not required. Examples are flat beds, pull-type utility trailers, etc.
Drop spindles are used when the lowest possible ground clearance is desired. Examples are Livestock and Horse Trailers, Car Haulers, Enclosed Cargo Van Trailers, etc.

A: Spring Centers are the CL (centerline) measurement of the Spring Mounting Pads on the axle. (Usually matched to the approximate frame width of the trailer.)

A: The Bolt Pattern of the axles can vary depending on the capacity of the axle. The Bolt Pattern also determines what type tire and wheel can be used. If there is a specific tire and wheel you would like to use. please relay that information so we can help you to determine the proper bolt pattern and axle.

A: The next step is to determine the length of the axle. Of the several ways and industry terms to describe this procedure. the most popular term is “Hub Face” which is the measurement from the base of the wheel stud to the base of the wheel stud on the opposite end of the axle.

Another term frequently used is “Track”. Track is the center of the tire to the center of the opposite tire. This measurement varies depending on what type of wheel used because each type of wheel (White Spoke, O.E.M., Custom) could have a different offset and this changes the tire center.

A: There are two basic types of springs to choose from: Double Eye or Slipper Springs . Double Eye Springs are used on the shackle-type suspensions.
Slipper Springs are the heavy-duty type of springs used with slipper-type suspensions and will provide longer and more rugged service.
Springs are sold with axles in sets of (2 each) and (1 each) U-Bolt Kit per axle.

A: There are several Hanger Kits to choose from — single, tandem or triple for double eye or slipper-type springs. Complete Hanger Kits consist of the Equalizer and Spring Hangers to attach to the frame. Shackle Straps (if double eye springs). Equalizers for tandem or triple Hanger Kits. Hangers and all the necessary bolts and nuts to attach the Equalizers, Springs and Shackle Straps.