Leaf springs are made up of a main leaf, with eyes on each end that hold bushings and bolt to the vehicle. Multiple other leaves carry the weight of your rig. There are numerous options for how to configure these packs of spring steel to perform under your vehicle. They vary greatly not only in quality, but in price and performance as well. When we purchase aftermarket leaf springs, we are generally looking for springs with increased arch to allow the fitment of bigger tires. How this is accomplished will dictate the ride quality and amount of articulation.
Longer leaf springs don’t have to deflect as much as shorter leaf springs to provide the same amount of wheel travel. But, unless you plan to cut the existing mounts off of your vehicle’s frame and add new ones, you are generally stuck with the same length spring that came from the factory. Springs made up of many thin leaves will offer a more supple ride than springs that use just a few thick leaves. The problem with many thin leaves is that there can be friction between each of those leaves. High-end spring packs solve this issue by tapering the leaves, so they are thinner at the ends. They also use Teflon pads between the leaves to reduce friction.
Other features to look for when shopping for leaf springs include bolt clamps, shot-peened leaves, and military wrapped eyes. A military wrap is when the second leaf wraps around the main leaf at the eye to retain the spring in place in case the main leaf breaks. Shot peening the individual leaves makes them stronger and more resistant to fatigue. Bolt clamps are preferred to regular crush style clamps since they cause, you guessed it, less friction.