2WD C10 Modern/Performance Alignments

[BMERDOC]

Thanks Rob!! No pressure there!! I will say that I've known about you and your company for years now and I feel like someone who likes Bball having a NBA player wanting to come out and watch them play!

I will say that after reading your thread it made me have to start over and relearn Toe. I think I may owe TR65 an apology about his take on toe. I am still trying to figure it out. I am researching info on the topic. I am still convinced you can't go wrong with an average of the Specific Range but I am having to reassess my beliefs in toe out (negative) vs. toe in (positive) vs. 0 toe. Currently I am pacing the floor, trying to visualize how a rear wheel drive vehicle has a tendency to induce 0 or toe out.

I'm processing all the info I have gained on my truck and will have it back on the rack soon. I hope to have some good info soon!

[BMERDOC]

I think I should have tilted this "One man's attempt at trying to get a decent alignment out of an old truck"

[BMERDOC]

Oh yeah. It was pointed out to me that all my specs are in degrees and minutes. I will be posting more sheets in straight degrees and in fractional toe. My reason for adding so many printouts and alignment screens is so that you can see them and study them so that when you examine a printout later you will have practice at looking at them and be able to focus. Kinda like sparring before the big fight.

[oldblue1968chevy]

Wow man your really putting the time thought into this!!

[BMERDOC]

Originally Posted by oldblue1968chevy

Wow man your really putting the time thought into this!!

I have seen threads asking about alignments and since I have an alignment machine and an old C10 at my disposal I thought it was my duty to offer any information I could to you guys.

[KQQL IT]

My 73 is lowered by cutting two coils. And longer bolts to get the camber decent. 1/2° positive.
and flipped out back.

And have found laying 6° and. 6 1/4° of caster. And a 1/16th of toe
has made for nice mannered good tire wearing alingment.
ill have see if the alingment sheet made it home.
im curious to your thoughts on this?
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[BMERDOC]

Double check that camber, I'd like to see it -.5º not positive. The caster is fine. 1/16th per side is fine. (1/16th = .12º = 07')

I'd love to see pics of the alignment at the upper bolts and specs on your ride height. Thanks for sharing!

[KQQL IT]

Did it positive because of the wild camber gain with out spindles.
Ill dig up a pic of upper A-arm.
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[KQQL IT]

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[BMERDOC]

KQQL IT,

I'd love to see what the alignment looked like if all the rear washers(?) removed, an equal amount removed from the front and the toe reset to your spec.

[KQQL IT]

Major negative camber.
And yeah washers cant fall out.
those are 4" bolts
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[BustedTruck]

I am replacing both upper & lower control arm shafts & bushings. I am thinking of turning the shafts to move the lower control foward and the upper control arm rearward. The idea is to get as much caster as possible. Any thoughts on this?

[BMERDOC]

I first saw this modification in Rob McGregor's Make it Handle thread (post 354) http://67-72chevytrucks.com/vboard/s...=419251&page=9
I can't argue with it from what I've seen. As long as done correctly and correct clearance is maintained, its good. I was thinking about doing it myself. The upper would only have to be shimmed to correct camber (ok maybe a little to equalize caster). I think it is a good low buck way to dial in a better alignment. My only question, what effect does it have on the tie rod/steering arm arch when the arm is moved? I don't think it would make much difference but I am curious.

[Ackattack]

I have been reading/researching alignment specs and doing alignments yourself at home (tape measure and string style). Any instructions on doing this? If not, when I get to it, I'll post up my "how to".

I also created a handy dandy spreadsheet that will calculate all of the angles for you, if you measure from your string line to the wheel lip (in mm) that I'll cover in my write up as well.

[BustedTruck]

I like the ball joint mod, but I have 15" wheels right now so it wouldnt work for me. I am just thinking while I have the arms in my hand, I might just try to get a little extra caster.

[gringoloco]

Originally Posted by Ackattack

I have been reading/researching alignment specs and doing alignments yourself at home (tape measure and string style). Any instructions on doing this? If not, when I get to it, I'll post up my "how to".

I also created a handy dandy spreadsheet that will calculate all of the angles for you, if you measure from your string line to the wheel lip (in mm) that I'll cover in my write up as well.

Have you looked at the FASTRAX camber/caster guage? Interested in your write up...

[Ackattack]

Originally Posted by gringoloco

Have you looked at the FASTRAX camber/caster guage? Interested in your write up...

No, I haven't looked at any tools yet.

This is funny: my Ipod touch has a digital level in it that reads out in degrees. You can calibrate it, so I figure that is going to be acurate enough for measuring the camber.

[gringoloco]

That actually sounds like a good idea
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[Ackattack]

Originally Posted by gringoloco

That actually sounds like a good idea
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I was just looking at the alignment tools available, several differnt brands from summit, and most of them read to the .5 degrees on caster/camber. If I remember right, the ipod app I have reads to .1 degree. For all I know (right now) there may be a specific alignment app for it.

If not, maybe I should develop one and make millions. Not that I know how to make an ipod/iphone apps nor would I make millions.....oh well....free idea for someone.

[BMERDOC]

Originally Posted by BustedTruck

I like the ball joint mod, but I have 15" wheels right now so it wouldnt work for me. I am just thinking while I have the arms in my hand, I might just try to get a little extra caster.

I saw that control arm modification and I have ZERO faith in my welding in a structural/safety enviroment!

As far as tools the toe and caster/camber gauges are good. You can one up that with alignment tables, steering and brake locks and a wheel leveler. When doing a home brewed alignment don't forget to center and lock down the steering wheel so its on-center when the job is complete. Nothins gonna rain on your parade like having your fresh alignment tracking straight and true only to have that pretty steering wheel pointing at 10 or 2! As far as string alignments go the only thing that they have in common that I DO NOT LIKE is that they are two wheel alignments. If it were me I'd find the centerline of the chassis and base my toe settings off that.

[BMERDOC]

Oh and BTW, google iPhone alignments. People have been doing it since the first Level apps came out!

[robnolimit]

BMERDOC, hey, can you you explain Thrust angles and rear steer, how about rear camber and toe (I know, this is for IRS cars) I am getting a lot of questions about this, and you are probably better versed to answer. Thanks.

[Ackattack]

Originally Posted by BMERDOC

I saw that control arm modification and I have ZERO faith in my welding in a structural/safety enviroment!

As far as tools the toe and caster/camber gauges are good. You can one up that with alignment tables, steering and brake locks and a wheel leveler. When doing a home brewed alignment don't forget to center and lock down the steering wheel so its on-center when the job is complete. Nothins gonna rain on your parade like having your fresh alignment tracking straight and true only to have that pretty steering wheel pointing at 10 or 2! As far as string alignments go the only thing that they have in common that I DO NOT LIKE is that they are two wheel alignments. If it were me I'd find the centerline of the chassis and base my toe settings off that.

Where do you get that turning table and steering wheel lock. Especially the turning table would make things way easier.

I am planning on measuring the thrust angle of the rear wheels too, but its gonna kinda be a pain.

[gringoloco]

Harbor Freight has tables, but you can use a couple of pieces of cheap tile and some bearing grease...

[BMERDOC]

Per Rob's request:

I'll try to make this simple. Thrust angle is the relationship between the rear axle and the centerline of the chassis. As I had stated before, Thrust should be zero. If the centerline of the axle is 90* to the centerline of the chassis it will be zero. Just like the front toe, toe out is negative and toe in is positive. If the thrust angle points to the left of the chassis centerline the thrust angle is negative, to the right, positive. This angle is the average of the two rear toe angles which is not to be confused with total toe which is, well, the sum of the two toe angles. If the thrust angle is negative the truck will want to rear steer to the left causing the truck to want to go right. You would have to add constant left hand input causing the "dog tracking" look. Of course, the opposite would be true if the thrust angle were positive.

Camber can have an effect on tracking too. No matter wether its front or rear. Lets stick with rear camber. A vehicle will tend to steer toward the more vertical or positive cambered tire. Lets try a small quiz...if my left rear camber is 0* and my right rear is negative .75* which way would the rear of the car wanna steer?....
....
....
If you said left then you are correct. It would want to rear steer left and you would have to steer left to cancel it out. Both camber angles must closely match so as to not cause a "pull" or "drift".

Caster has NO affect on the rear axle...unless, in the off chance, you have a four wheel steer car. If that was the case it would closely follow the rules of front caster. Although I won't go into 4W steer it did remind me of a good point.

Rear angles have a greater effect on how a vehicle tracks. Anyone who has driven a forklift knows they can be very twitchy.