Hellwig LP-35 Load Pro SeriesRear Helper Springs (3510) by Hellwig Progressive Load Leveler. 4 Leafs Stack. This is a set of secondary helper leaf springs designed to add up to 3,500 pounds of load support to restore comfort and stability at the rear of your 3/4 tonor 1 tontruck.
The 4-leaf design progressively adds support as OEM leaf springs become loaded and compressed. Crafted from heat-treated ASTM 5160 alloy spring steel for maximum strength and resilience, these feature a spring rate that becomes firmer as pressure increases.
Recommended for heavy hauling, work truck use, or pulling a 5th-wheel RV trailer, these maintain proper ride height and prevent original springs from sagging due to sustained load compression. Requires Mounting Kit for installation (sold separately). Drilling may be required.
"