Leaf springs have been used since the days of horse drawn carriages, and are still found on the back of new pickup trucks today for one simple reason: they work! Leaf springs locate the axle fore and aft and side to side, hold up the chassis, and provide excellent load-carrying capabilities. That doesn’t mean that they are all the same, though. Even if the design is old, there is the potential for a surprising amount of technology in a high-quality leaf spring.
When it came time to replace the leaf springs on the rear of this Toyota pickup, we ordered a set of Trail Gear 3-inch lift springs from Summit Racing. Trail Gear springs are packed with features that allow them to provide increased articulation and a smooth ride while withstanding the rigors of off-road use. These springs are 56 5/8-inches long, requiring new front frame mounts. Why go through the trouble? A longer spring does not have to arch as much for a given amount of up-and-down movement as a shorter spring. We had previously built custom low-profile mounts on our frame, but Summit Racing carries Trail Gear spring hangers for those starting from scratch.
In addition to being longer than the factory leaf springs, the Trail Gear springs pack the latest technology into one of the oldest suspension designs. The springs are made from shot-peened steel and feature diamond-cut and tapered individual leaves with PTFE sliders between them that maximize articulation and can withstand millions of cycles without fatigue. All leaf springs are not created equal, but these Trail Gear springs have improved our suspension articulation and ride quality without the need to convert to an expensive and complicated link suspension.
If we had an old dog, Trail Gear could likely teach it some new tricks.