Spring Fling: Improving Articulation and Ride Comfort with Higher Quality Leaf Springs

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The Trail Gear leaf springs use seven thin leaves that allow each leaf to have a lower spring rate and be softer when compared to springs with less leaves that are thicker. This might not be intuitive since the spring pack looks so thick, but the spring rate is only 235 pounds per inch.

The military wrap on the fixed end of the spring is a great safety feature. Even if the main leaf (topmost, longest leaf in the pack) breaks, this military wrap will allow us to limp off the trail without the axle falling out of the back of the truck.

These bolted spring clamps prevent the leaves from fanning out, yet they do not hinder suspension motion like a traditional spring clamp can do. Trail Gear knows all of the tricks required to get the best ride quality and most articulation out of a set of leaf springs.

The Trail Gear springs include polyurethane bushings that are fluted to accept grease. We greased the bushings with standard wheel bearing grease to limit wear and squeaks on the trail. Also note not to overtighten your shackle bolts or they cannot move freely within the bushings.

We had already fabricated new spring mounts that are low profile and slide over rocks and other obstacles. Trail Gear offers similar mounts to put their leaf springs under just about any 4x4 with body-on-frame construction.

We used an engine hoist to lift up the back of the truck and unload the springs, then set the axle down on jack stands. This made the process of swapping leaf springs simple. If you do not have a cherry picker, a tall set of jack stands can be used under the frame with a second set of shorter stands under the axle. (Image/Harry Wagner)

The new Trail Gear leaf springs provide excellent articulation on the trail in a simple, cost effective package. Before tossing your leaf springs for links and coils, remember that not all leaf springs are created equal.

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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.