Guides
Leaf spring guides from the factory floor
APM has manufactured leaf springs since 1971. These guides answer the questions we get every week: which spring is on my truck, why is it sagging, and what should replace it.
Start here
Three questions, three answers
-
How to identify a leaf spring
Find the stamped part number on your spring, decode Ford stampings, or identify by vehicle and measurements. Then search the number in our catalog.
Read the guide -
Truck sagging on one side?
A five-minute diagnosis with a tape measure, why springs fatigue, and what actually fixes it. Hint: replace the pair.
Read the guide -
Leaf count, capacity, and ride
What 4/1 versus 7/1 really means, how two-stage packs work, and how to spec a spring for the load your truck actually carries.
Read the guide