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Mike_82_Shortbox · 01-07-2012, 02:44 AM

Nick,

Thanks for the lengthy discourse on your alignment specs and theories. It got me on the right track for my 82 Chevy Shortbox. I recently replaced the upper ball joints, idler arm, pitman arm, and all the tie rod ends, but had to have a shop do the lower ball joints, since I had no press and couldn't even get the old joint tapers to release. That shop also did an alignment.

The truck drove worse than ever, and I mean ever! So I started asking questions, and I found a shop where the guys had fixed a lot of Chevy frames, where they crack at the steering box, and who said that they regularly put 8° of caster on big 4-wheel drive pickups, whereafter they drive like a dream.

I tried to take the truck back to the original shop, but my appointment time came and they blew me off, so I demanded a refund, and took the truck to Les Schwab, where they have the same alignment machine as in your pictures. Sweet!

My thrust angle started out (left) at -.35°, and I can't do anything about that.

Eight degrees sounded a little extreme for me, but I liked your idea of a lot of caster.
I requested 3.5° of caster on the right, and 3.25° on the left, and got 3.7° right and 3.3° left. Pretty good, and still within a half-degree side to side.

I liked your argument about camber, but the book and the alignment tech said slightly positive, and exactly equal side to side, so I ended up with .5° positive camber on both wheels. OK.

The tech said it was the difference in caster that compensates for road crown pull, but I still like the idea of slightly less camber on the left.

Finally, the book calls for .13° to .25° toe-in (.26° to .50° total), and using your midrange method, that puts each wheel at .18° with .36° total toe-in. I ended up at .20° for a total toe of .40°, which is right about the midrange average. OK.

The bottom line? The truck drives like brand new now, and if I feel like I want to tweak something in the future, Les Schwab said they would happily do it, and not turn me away when I set an appointment. The alignment cost me $56 there.

So anyway, you gave me a big push in the right direction, and if you're still out there, thanks.

Mike

01-07-2012, 02:44 AM	#85
Mike_82_Shortbox Registered User Join Date: Jan 2012 Location: Portland, OR Posts: 37	Re: 2WD C10 Modern/Performance Alignments Nick, Thanks for the lengthy discourse on your alignment specs and theories. It got me on the right track for my 82 Chevy Shortbox. I recently replaced the upper ball joints, idler arm, pitman arm, and all the tie rod ends, but had to have a shop do the lower ball joints, since I had no press and couldn't even get the old joint tapers to release. That shop also did an alignment. The truck drove worse than ever, and I mean ever! So I started asking questions, and I found a shop where the guys had fixed a lot of Chevy frames, where they crack at the steering box, and who said that they regularly put 8° of caster on big 4-wheel drive pickups, whereafter they drive like a dream. I tried to take the truck back to the original shop, but my appointment time came and they blew me off, so I demanded a refund, and took the truck to Les Schwab, where they have the same alignment machine as in your pictures. Sweet! My thrust angle started out (left) at -.35°, and I can't do anything about that. Eight degrees sounded a little extreme for me, but I liked your idea of a lot of caster. I requested 3.5° of caster on the right, and 3.25° on the left, and got 3.7° right and 3.3° left. Pretty good, and still within a half-degree side to side. I liked your argument about camber, but the book and the alignment tech said slightly positive, and exactly equal side to side, so I ended up with .5° positive camber on both wheels. OK. The tech said it was the difference in caster that compensates for road crown pull, but I still like the idea of slightly less camber on the left. Finally, the book calls for .13° to .25° toe-in (.26° to .50° total), and using your midrange method, that puts each wheel at .18° with .36° total toe-in. I ended up at .20° for a total toe of .40°, which is right about the midrange average. OK. The bottom line? The truck drives like brand new now, and if I feel like I want to tweak something in the future, Les Schwab said they would happily do it, and not turn me away when I set an appointment. The alignment cost me $56 there. So anyway, you gave me a big push in the right direction, and if you're still out there, thanks. Mike Last edited by Mike_82_Shortbox; 01-07-2012 at 02:50 AM.