I rebuilt my front suspension this year. I replaced pretty much everything but the steering box. All moog pieces, tie rods, center link, idler arm, ball joints, a-arm bushings, front springs. I also put on new kyb struts, monroe strut bearing plates and replaced the sway bar bushings and end links. I was careful to trace the outline of the old strut mounts and lay the old ceterlink and tie rod assembly next to the new one so my alignment would be close enough to get to the shop without killing my tires.
I went to a chain tire store because it was the closest to my house. They mounted my new tires(used stupid wieght clips instead of inside tape weights which scratch the wheels clear coat) and did my alignment. When I got home I noiced that they didn't touch the Caster at all and it was out of spec range. I went back and asked them to realign it and they came out an hour lated and said it is dead on.
I pointed out that the factory caster setting is 5* +/-.5 (from my gm helm manual) even their printout show specified range as 4.3-5.3. My actual caster is 2.9*left and 3.1* right. He said that it won't affect tire wear, the camber and toe are dead on(which they are) and they can't adjust anymore caster on my car without a "shim kit". If I wanted to pay he'd be happy to order one.
Are these guys jerking me or what? Is the caster being that far off bad? It pisses me off that I spent so much time and $ on the suspension and not have the alignment right and have these guys act like I'm bothering them.

Sorry for the long rant but I'm pretty frustrated.

 

Well, the caster is obviously not "dead on" to factory spec. However, it's true that the tires won't wear from this as long as the caster is close to equal on both front tires. It's also possible that they have it as far as they could get it - the position of the front subframe relative to the strut towers could account for the inability to set things just right. Look and see if the strut shaft is as far back in the hole as it can go, and if the bolts are as far back in their slots as they can go. If so, they aren't blowing smoke at you. You might be able to loosen the bolts holding the subframe in and move the whole thing forward, thereby increasing the positive range of caster. And of course, some caster/camber plates could help this adjustment if it's the bolt holes holding the caster adjustment back.

You may decide you don't need it, however. The loss of roughly 2* of caster will lighten the centering force on the steering wheel somewhat. It also reduces the desirable camber gain you get when you turn the steering wheel. But if it's the bolt holes holding your camber back, then the lower caster amount also gives you more room to use negative camber if you want. How does the steering actually feel to you when you drive it now?

 

Thanks for the reply. I will check the position of the strut shaft tommorow when it's light out. The car seems to track ok, doesn't really feel like it's pulling one way or the other. For as much work as I did to the front I have to say that the steering feels a little loose. I was wondering if that was because the steering box or the alignment was off. Maybey loose isn't the right word cause there isn't a ton of play in the steering wheel, just not as responsive as I had expected.