Need alignment help!

Added new suspension front and rear. Rear with all new ICON adjustable bars. Track and trailing arms. What should a stock 4runner limited be so that I can make sure I have the right numbers.

 

What height? Aftermarket control arms? It was suggested that I went 3-4 degrees caster, as close to 0 degrees camber as you can get, and factory setting for "toe in". This is with a 3"/2" lift /leveling kit, JBA UCA's, 275/70-17 tires.

 

I the front is great. Its the rear I changed everything on and they are all adjustable. So I need the rear readings if anyone can help?

 

Add the 2 inch rear icon springs
Icon rear lower link kit adjustable
Icon rear upper link kit adjustable
Icon rear adjustable track bar

 

Since the rear end is NOT independent(solid rear axle) the rear is going to be centered, as to not make the Runner "dog track" front to rear, and rear track bar measured to stock length. The upper and lower links are adjustable to get pinion angles correct as to not bind "u-joint" on travel up and down. Since these are "double cardan" u-joints, a straight pinion/ output shaft angle is good.

 

Icon has installation instructions on their website as well, depending which system you have.

 

For rear, just make sure the links on each side are of equal length; from there, you're just making sure the axle is centered, and your pinion angle is good. These aren't things that a typical alignment shop will look for, or probably even touch (aside from if your thrust angle is off, they might adjust the front to compensate).

For centering of the axle; it doesn't need to be perfect - just make sure the tires/wheels are roughly the same distance from the wheel well. For the pinion angle... if you don't have driveline vibes, I'd consider it good. If you do, using an angle finder or digital angle gauge, adjust your lower links to rotate the axle, until the pinion and the driveshaft are around 1-2 degrees of each other.

 

Its just that after the 2.5 lift front and 2 in the rear. My MPG went from 18.7-19.4 down to 15.4. Same tire size. Makes me think that the rear is off somehow. We did verify the width its off by 1/16th

 

My friend has alignment rack and I just need to see the factory rear settings and see if I can get it close to those. But maybe I'm over thinking it?

 

The factory settings are pretty straight forward..... Where it gets bolted to the frame is where it resides. The adjustable lower and upper control arms allow you to "fine tune" the rearend being straight in relation to the front end. In drag racing we adjust pinion angles to "shock" the slicks less or more depending on E.T's and traction, but the one thing that remains a constant is the rear end must be straight with the front. The decrease in MPG's you are seeing is the amount of air that is now going under and around the vehicle less efficiently causing parasitic drag, hence lower mileage. Like we were told long ago..you can't always have your cake and eat it too! It's the nature of lifted vehicles to drop in mileage, it's happened to every one I've owned. How's the pinion angle? kbp810 has some good advice in post #7...... 1-2 degrees.

 

Thanks alot. That all makes since. And thank you.

 

Thank you guys for all your input and being patient and very informative