How bad is this?



The adjusters are maxed out trying to get the camber close, which is why the caster is so far off. Do I need to invest in those offset bushing/bolts or will this be fine?

 

I'm not an expert by any means, but according to my research GM spec on caster is 3.75 plus or minus 1 degree. That 6.6 is way out of spec. Not sure what the effect would be.

What numbers are you shooting for on camber? GM spec is 0.25 plus or minus 0.5, so you have room on both sides to pull the UCA in some...

 

If I understand the adjusters correctly, pulling the front one in some should decrease both camber and caster.

 

I am not an expert but from what I do know, here is my opinion of your settings above (along with the most recent setting on my truck granted it is 2wd):
Camber - should be slightly negative to account for a positive shift when going into a turn or on a hard launch with front end rise. (mine are -0.3L and -0.4R)
Caster - a good performance setting would be on the forward edge of stock settings which will allow a little firmer steering. Cross Caster should be -.25 to -.5 degrees (pass side farther out) to track straight on crowned roads. (my latest settings are 5.0L/5.3R)
Toe - dont really see anything wrong with your toe. A little inward toe will help with straight line tracking but too much will contribute to unnecessary tire wear. (my latest settings are 0.05L/0.04R)
This is all based off recollection of the research I did before taking my truck in for alignment after changing a few front steering components earlier this year.

 

I don't know anything about that computer alinement or GM's spec, but based off the hundreds of race car alinements I have done and what I know about how these measurements affect driving and what not, here is what I would aline my personal truck at.

Camber, about -.5* or less L & R

Caster, 3* on the left and 3.5* on the right. Extra total caster won't affect tire wear, it will just make the truck want to come back to center or "neutral" easier. Just keep it about a .5* split to help hold it on the road crown.

As far as toe, here is where I disagree with ALL car manufactures. They all want a little bit of toe IN. Well that makes no since, ya it helps keep the slop tight, but really scrubs the tires when you are in a turn. Ever notice how when you turn hard, the tires howl and "walk over each other??? IMHO, you need about a total 1/8" of toe OUT.

The inside tire is on a smaller radius then the out side tire in a turn, so it should be turning into the turn more right? This is called ackerman steering and any race car guy can tell you about it.

 

Is the truck stock?lowered?lifted?

If its lowered that would explain your higher caster numbers because when you reduce the rake on these trucks by lowering the rear the frt caster increases which isnt a bad thing. If your lifting the truck and leveling the rear the caster usually decreases but again isnt a big deal.The big deal with your caster is the difference from side to side,which the right side should be 0.50 higher than the left no matter what the number/value.

The camber IF lowered and "maxed" out can be changed as you have too much positive camber anyway. The left frt 0.30 could be dropped to -0.20 by letting the rear cam bolt drop in which would decrease your camber and increase the caster at the same tike.The right side 0.80 could be dropped on both bolts 0.50 per side to get the camber to -0.20 while keeping the caster close to where its at IF the left side caster gained closer to the left on the adjustment.

Even if the truck is lifted you really dont need a ton of positive camber,and I usually try for as close to zero camber as possible.

The whole alignment really relies on IF the cams are totally maxed out or is there actually more adjustment. Maxed out meaning all the positive camber allowed,which if its maxed out that way I see where you could drop both sides on the camber to get your caster closer to each other.

 

Atomic, what specs did you end up going with? I finally got around to installing the offset bushings and plates, should finish up tomorrow. When I go in for an alignment, what specs should I be shooting having installed coil-overs?

 

I tried to have them set it up as straight as possible since it was mainly for racing, maybe some slight toe in. My front end steering has a ton of slop in it though, not sure if its just worn out stuff or the heim tie rods, but once he got it set I wiggled the tire a little bit and it was way out all over the place.

The coilovers shouldnt affect the alignment specs at all, factory specs is probably what you should shoot for.

 

Oh, I didn't mean to imply coil overs would directly effect alignment. It's just that I have a similar setup. I'll go for factory specs then. I think the bushings and plates add an additional 3°. I'll have to measure, but I believe I'm around 32" to the fender lip. I may go down 1 more inch in the front and give my truck a slight rake. I'll play with it more next weekend.

Thanks for your help.