OPTI-RATE REPLACEMENT LEAF SPRINGS for SPRINTER 3500 4x4 (PAIR)

Our Opti-Rate spring pack represents the culmination of over a decade spent tuning leaf springs for various ride heights, payloads, applications and uses. Built out vans often suffer from harsh bottom out due to the constant weight being carried, and will drive very poorly overall. Previously, leaf springs had to be ordered to a specific weight range and lift height, which meant either guessing or waiting until completion to order parts. The Opti-rate spring gives new flexibility in tuning both your spring rate and ride height, all in one package.

In the relentless pursuit of improvements, we have lengthened the spring over 2" and developed a longer shackle to improve ride. The angle of the shackle has a direct effect on the behavior of a leaf spring, with a longer spring and shackle combining to make for a more stable and progressive spring curve, and taking out much of the harshness associated with leaf springs.

With an industry first tunable preload system, we've developed a spring that truly is a 'one size fits all' solution, perfect for van builders, kit installers, and DIY'ers building their vans step by step on their own. The Opti-rate spring is made up of 3 distinct parts: the main springs in the primary stage, a 3-leaf secondary stage, and the Adjustable Preload Spacers (APS). The Adjustable Preload Spacers are machined blocks with stackable delrin glide pads that preload the secondary stage into the main stage. The springs are designed in a way that there is a gap between the 2 stages, perfect for adding our billet machined APS. When the main spring is weighted, the APS are able to engage the primary and secondary stages together. Changing the preload spacers requires little more than a floor jack, socket wrench, and a mallet; the springs can stay in the vehicle.

For light vans, or customers wanting the softest ride, no APS is needed and the spring works in its softest configuration. Middle weight vans, or customers wanting a firmer rear spring rate and increased ride height can add the APS with 1 delrin glide pad. Heavy vans, or customers wanting the maximum spring rate and ride height can install the APS with 2 delrin glide pads.

This spring is designed as a tunable solution, and as a way to correct spring rate. We've designed this spring to return the lost ride height without adding excessive lift. These springs are fully compatible with lift blocks and existing rear geometry correction components to allow for our 2" lift kits to work perfectly for those that want increased clearance and a more aggressive stance.

To learn more about the theory, principles and development that went into our Opti-Rate spring system, please read this article in our blog.

These require truck freight to ship, if you have a commercial address this will help save on the shipping costs.

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