Something about the spring over axle setup makes axle wrap a much bigger issue than with a spring under setup.  Axle wrap is when your pinion rotates up or down when you give the engine gas, which makes it much easier to break u-joints, driveshafts, pinions, etc.  Also, as soon as you add larger horsepower engines to your truck (V8’s and such) it also makes axle wrap much more possible.  You can counter act axle wrap a few ways: stiffer springs, longer perches, or a traction bar. 

Stiffer springs are good but have other effects (like a stiff ride) so are not always the best option.  Longer spring perches are a poor way to counteract axle wrap in my opinion, and gives the perches potential to bend.  The only real way to counteract axle wrap is to use a traction bar.  Traction bars are basically devices that allow your axle to pivot up and down as the axle requires for articulation and general suspension use, but does not allow the axle to “rotate” back and forth.  You can either make and install a traction bar, buy one and install it yourself, or have a reputable shop build and install it.  In any case, there is no “uniform” setup for them, and in each case they are generally “custom” and will need to be welded on.  Ih8mud.com has a lot of information about traction bars if you search around.

Here are some good examples:
One by JK Customs of Roundrock, Texas.
x

And another setup by Decker's Land Cruisers:

 

Next page:
5. Cutting and Turning Your Front Axle
Back to SOA Main Page