When recentering the rear axle should I do upper or lower control arms?

 

Edit: I'm dumb. And need coffee.

 

If you mean centering it in the wheel wells, lower control arms are going to give you that adjustment you're looking for. Uppers are mainly used for correcting pinion angle.

 

Thank you sir! Exactly what I needed to know.

 

When you only get one set, they do the same thing, just backwards of each other. Uppers will move the top of the housing forward or backward. Lowers will move the bottom of the housing forward or backward. For the rear axle, will you be wanting to raise or lower the pinion? Probably raise it? Which means either going longer on the uppers or shorter on the lowers. So, you either move the top of the housing back - or the bottom of the housing forward. And moving the bottom of the housing forward brings the tires even further toward the pinch seam...

If you get both sets, then you can move the entire housing forward or backward, and set the pinion where you want it. In this case, the conventional wisdom is to use the lowers to center, and the uppers to set caster/pinion.

 

I did just adjustable rear uppers to correct the pinion angle and as a bonus, it moved the axle back about 1/4" closer to center.

Adjustable rear lowers are next on my list.

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You use a complete set up uppers and lowers.

 

Hows this possible the axle rotates ?

 

The lower control arm mounts hang below the axle tube. So pushing the upper back will also move the axle tube (center of wheel) backwards also. You probably get about half as much movement at the axle tube (center of wheel) as the length you extend the upper arm back.

 

Right, you have to take into account where the axle actually pivots from not the center of the axle.