HOW TO MEASURE TRAILER LEAF SPRINGS
- Match the existing spring according to its shape and type (double eye, slipper-open eye end, slipper-hook end, slipper-flat end, or slipper-radius end), Length and Width.
- Count the number of leaves, each layer of spring metal is considered a leaf.
- Measure the length of the spring when the spring is not under load (jack up trailer by the frame), this is the free length of the spring.
- Measure from the center of the front bushing in a straight line to the center of the rear bushing for DOUBLE-EYE and OPEN-EYE leaf springs.
- Measure from the center of front bushing in a straight line to the end of spring for HOOK-END, FLAT-END and RADIUS END leaf springs.
- The inside diameter of the bushing in the attaching eye of the spring needs to match the shackle bolts and spring hanger holes used to mount spring.
- An inside diameter of 9/16" is the most common size, but some older trailers used 1/2" bushings/bolts.
- Every leaf spring we sell is supplied with a 9/16" ID bushing in the closed eye
- Also note that spring capacity is given per each spring-thus a 4,000 lb. rated axle should be matched with two 2,000 lb. or higher capacity springs.