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Spring over or under


Well-Known Member
I have see some Ranger 7S that have the stock configuration off the spring (Over the axle), but have heard and also see (On the Andrews Racing 7S) that they use the spring under the axle.
Which configuration do you think its better for a Daily Driver, Pre Runner Ranger?? How much wheel travel can you make with the spring under configuration??

Mexican PreRunner


Well-Known Member
if anything you would lose wheel travel because the axle would bottom out before the springs and be a couple inches less

how ironic is it that most people slow down for speed bumps yet almost all of us here im sure pin it


Well-Known Member
You never want a leaf spring to go completely flat if you want any life span out of it. Unless your springs are made from something like 300M, you definitely do not want to go into reverse arch. To go spring over means either a really flat spring (with little travel), or a really tall vehicle. If you're stuck with spring over, then the partial cure is to go really long on the spring and move the mounts up on the frame. With spring under you can have a mildly arched spring and low ride height at the same time.
Another advantage to spring under is that the axle centerline is closer to the line drawn btwn the front & rear spring eyes. This helps to control spring wrap as the axle has less leverage on the spring than if it is spring over. Take a look at the overload leaf on a stock Yoter 4wd. They are spring over trucks. At the rear of the overload leaf is what looks like a leaf minder. It's not, it is a traction/anti spring wrap device. When the spring gets partly wound up, the cross piece contacts the main leaf and makes the overload act as a traction bar. With spring under you are less likely to need such articulation and travel limiting devices.


"Teach you all I know and you're still stupid"
-- Howdy Lee


Well-Known Member
ntsqd, I could not have said it better. The guy that built my truck did it that way for a couple diffrent reasons. Better in the tight and twisty and better spring life. The arch in my springs is a bit severe because the class has a max spring length and we had to do it that way to get the ride hieght we wanted. No travel was lost and back bend is not a problem we have to deal with.

J.C. Andrews
Andrews Racing
<A target="_blank" HREF=http://www.andrewsracing.com>www.andrewsracing.com</A>


Well-Known Member
definitely spring under. in fact-you can get more useable wheel travel without the nose bleed! under also reduces wheel hop. the arch in the frame allows the axle to enter the dead space without the leaves going into negative arch. this keeps the springs alive. i know, i have a straight axle toy 7s, and i have spent way too much money at national trying to get as much travel as possible. even just a few times past neutral and the springs wil go away. martin

If your gonna go, go BIG