Here are the five key factors to keep in mind when working with leaf spring suspensions for your classic car or hot rod.
Making of a good leaf-spring suspension is pretty darn easy if five basic rules are followed.
Use Multi-Leaf Springs
Rule number one for making a good leaf spring suspension is the use of multi leaf springs. Multi-leaf springs can be custom made, which would give you the ride quality and the right height you’re looking for. See our article on mono leaf springs.
Roll and Taper Your Leaf Ends
Rule number two for obtaining a good riding leaf spring suspended vehicle is make sure the end of the leaves are rolled and tapered. Rolling and tapering the ends reduces hysteresis which results in a nice riding vehicle
Never Adjust Your Ride Height With Blocks
The third rule is do not use blocks to either raise or lower the vehicle. The use of blocks is the leading cause of handling problems. You want to get that spring seat as close to the centerline of the axle as possible. This greatly reduces axle wind up.
Make Sure Your Shackle’s Angled Right
The fourth rule is shackle angle. We want the shackle to be right around fifteen degrees from vertical. An incorrect shackle angle increases the amount of force required to flex the spring, and the more force the harsher the ride
Choose The Right Shock
The fifth and final rule not only applies to leaf spring suspended vehicles, but all vehicles. That is choosing the right shocks. Older cars were not designed to use gas shock absorbers, they were designed to use hydraulic shocks. In fact gas shock absorbers can add up to 75 pounds for the initial force to get that spring to move.
It’s best to choose the shock by application and not by length, and finally use the best quality shock you can afford.