Trailer Spring Dimensions

Definition - The physical measurements of a torsional trailer spring are also know as the trailer spring's dimensions.

Trailer springs are torsion springs so, in order to assist you in dimensioning your trailer spring, we have provided you with our how-to-measure-torsion-springs diagram. In order to begin setting your trailer ramp spring dimensions tolerance, you must consider its surroundings.

How to Measure Trailer Spring Dimensions

how to measure a torsional trailer spring

Trailer Spring Direction of Wind

To determine your torsional spring’s direction of wind, you must consider where the static leg will be installed and in which direction the other leg will be traveling in. If your spring’s leg will be traveling clockwise, it is left hand wound. If your spring will be traveling counter-clockwise, the direction of wind is right handed.

Trailer Spring Outer Diameter

To decide on your trailer spring’s outer diameter, you must measure the surrounding parameters to make sure that the spring will fit. Once you’ve set a limit, make sure the outer diameter of your trailer spring is less than or equal to that.

trailer spring inner and outer diameter dimensioning examples

Trailer Spring Wire Diameter

Trailer springs are often heavy duty torsion springs which need to use hefty wire diameters so, to decide on your spring’s wire diameter, be vigilant of the space between the shaft and the other parts surrounding the trailer spring’s outer diameter. Also be vigilant of the inner diameter (below). The wire diameter mustn’t be too tight on either one of these dimensions; outer diameter and inner diameter. Once you’ve set a limit, make sure the wire diameter isn’t larger than that.

Trailer Spring Inner Diameter

To determine your trailer spring’s inner diameter, you must consider the fact that a torsional spring’s inner diameter contracts during deflection so there must be a few thousandths of an inch of clearance between the torqued inner diameter of your trailer spring and the shaft where the spring will be installed. Whatever this minimum tolerance is, make sure that the torqued inner diameter is greater than or equal to that.

Trailer Spring Body Length

When it comes to trailer springs, you will usually need more than one so you must make sure that the body lengths added together don’t exceed the provided space on the shaft. The lengths added together must be less than or equal to that provided space.

trailer spring installed over shaft showing its body length

Trailer Spring Free Position

To determine the free angular position of a trailer spring, you must first consider the position in which the legs will be place and how they will be torqued. Pre-torque is also a consideration since it can help your spring stay in place thus providing it with more stability.