The 4Deg Wedge is a angled piece of cast metal that goes between the rear & the leaf springs. You have to loosen the U Bolts, replace the center alignment bolt that holds the rear to the leaf spring. When you install the wedges the center bolt becomes shorter, thats why you have to change it. The rear sits in the center bolt for alignment.

Basically it changes the angle that the rear sits on the Leaf springs. This will eliminate wheel hop & rear sagging off the line. If you drive your truck everyday you may want to do like a 2 or 3 deg change only. It puts your U-joints under more strain since you have changed the angle of the rear. It really makes it launch good. On other thing I would do for sure is intall a driveshaft loop for safety.

I am not sure how many people have changed the pinion angle on their trucks, I know of a few. You may get mixed opinions but I am just telling you what I got. Its a old trick used for along time, nothing new.....

 

Thank you for the quick reply. For some reason, I thought it gad to do with placing a shim somewhere in the driveshaft area--duh!

I don't think I will do that but I appreciate the info--and, the JL drive shaft loop was one of my first mods. I had 'faith' that I would get into the 12s .

Dan

 

No problem, like I said its up to you, I know JL has changed his some & i think totaled my have as well. the rear shackle drop actually gives you about 1.5 deg changed as well...