Poor 74 front suspension alignment

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Poor 74 front suspension alignment

Post by builtnotbought on Mon Aug 22, 2016 5:46 pm

So another story from me about overcoming obstacles bounce  Laughing
This is my first time in life when I did shim's (washer's) alignment and it's crazy Laughing

Thanks Steve MCarlo77 for sharing with me an alignment specs from manual!
I don't know what radial PWR steer is so let it be belted. As for columns  I don't know too what to choose so let it be (1).
If somebody has info about this table too it will be interesting to read.


After that I've read some article about chevy's old suspension's specs and some guy from I forgot what suspension shop said that for a little improved handling specs must be:

Camber= -0.7* -1.0*  (* - degree)
Caster= +5*
Toe-in= 0

These specs are similar for some columns and not for others in the manual table for a-body. But it's very interesting that camber is most of the time positive. 

So, today car was sitting several hours on alignment stand and I with a wrench and a set of again "custom" shims (as align bolt is 13mm in diameter) I was trying to make some race car specs on stock A-arms and cross-shafts Very Happy
If serious I tried to make caster +5* plus camber -1* combo, and with stock length bolts I reached as I remember about +1.5* +1.8* caster with around camber 0* and there was no more bolt length to make more negative camber. It was race specs fail Very Happy

Besides that I noticed that drivers side took more shims than right...don't know why this happened, may be frame is not straight. Any experiece of alignment from factory or many years ago? How simmetrycal it was from factory?

So after not getting any race car I tried to make smth drivable combo of caster and camber for now. First caster about 0,5*, then camber about 0.1* - bolt lenght is over.


This is a screen of photo I got for now. No more high number degrees with camber and caster available as bolts are too short. Programm in PC still thinks that such 0.1* race camber is bad for me. It was green only near 0* camber. Rear end looks great after 40 y/o work and frame off.


Please tell me how can I get more caster and more camber on stock suspension (and do I need high degrees). Or what should I drill or cut or weld to get them Very Happy  Thank you!

One more question according to alignment, streering shaft position. It has line mark on the top and it should look straight up as I remember. Now with front wheels straight I didn't have mark on it's place. Questions are:

1. Is it true that steer shaft can be bolted to steering machine only one way, no upside down options (flexible mount with 2 bolts of different diameters)?
2. If first question is true, is it possible to turn shaft around steer machine (there is one star bolt between machine body and flexible mount) or it has only 1 position?
3. How can it hurt handling if steer shaft line mark is not vertical but has an angle? As I have new steer wheel with adapter with 2 bolt patterns, my steering wheel can't be mounted straight with steer shaft line mark vertical. It will have angle anyway.

Thank you
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Re: Poor 74 front suspension alignment

Post by fasrnur on Mon Aug 22, 2016 6:59 pm

I'm thinking that the first column is power steering with belted (bias ply) tires and radial referring to radial tires.
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Re: Poor 74 front suspension alignment

Post by g3chevy on Mon Aug 22, 2016 10:42 pm

Looks like your A-arm shaft is reversed. The side with the smaller gap should be against the frame.
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Re: Poor 74 front suspension alignment

Post by bigredlaguna on Tue Aug 23, 2016 12:24 am

I assume you made sure the steering gear was centered for the alignment, correct? If so, then to get the steering wheel centered, you simply have to adjust the wheel to center using the tie rod ends. Whichever direction you need the wheel turned, you toe in one side and toe out the other an equal number of turns. It shouldn't take a lot, test with 1/4 turn on each side to see how far the steering wheel is moved and adjust accordingly.
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Re: Poor 74 front suspension alignment

Post by clanceman427 on Tue Aug 23, 2016 6:44 am

Make sure your settings match your tire type. If you have radial tires use the radial alignment settings. Bias ply tires were still standard back then but radial tires were optional. They behave very differently and thus have very different alignment specs for the front suspension.
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Re: Poor 74 front suspension alignment

Post by chevellelaguna on Wed Aug 24, 2016 4:09 am

As far as the caster camber shimming issue is concerned you may need an offset upper cross shaft. I had issues with aligning my front suspension, same as you with too many shims needed on one side of the cross shaft, no one made offset shafts at the time. I just made my own alignment shims out of 1/2 steel plate, so I wouldn't have to mess with slipping in six or seven shims. I'm pretty sure I had to replace at least two of the bolts as well because they weren't long enough to have the nut tightened down far enough, with the thicker shim pack in place. Offset cross shafts would have solved my issues, but it drives and handles so well and doesn't wear tire that I don't think I'll ever really mess with it again. It tracks straight, comes out of hard corners and centeres itself, isn't "darty". Not much steering input is required.
Don't forget the rotational torque on a rear wheel drive car unloads the front suspension, that changes the camber on the drivers side and in turn shoves the passenger suspension down. The really old school alignment guys take that into consideration also the crown in the road can be slightly compensated for, on one side, as well as full tank of gas, just driver no passenger weight etc.
Toe should be as close to zero as you can get it on our cars, toe-in up to 1/16" per side is acceptable. That's waaaay better than factory specs some of which I've seen were 1/4" per side!
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Re: Poor 74 front suspension alignment

Post by builtnotbought on Wed Aug 24, 2016 6:08 pm

fasrnur wrote:I'm thinking that the first column is power steering with belted (bias ply) tires and radial referring to radial tires.
Wow thank you, don't even thought that it is about tires!
g3chevy wrote:Looks like your A-arm shaft is reversed. The side with the smaller gap should be against the frame.
I checked today, cross shafts are installed as they must be, Wheel side is turned to the wheel. Of coarse I examined and can tell that I can rotate cross shaft the other side and it will give me more camber, but is this legal (safe) to install cross shafts this un factory way? I guess that it is but need to confirm.
bigredlaguna wrote:I assume you made sure the steering gear was centered for the alignment, correct? If so, then to get the steering wheel centered, you simply have to adjust the wheel to center using the tie rod ends. Whichever direction you need the wheel turned, you toe in one side and toe out the other an equal number of turns. It shouldn't take a lot, test with 1/4 turn on each side to see how far the steering wheel is moved and adjust accordingly.
As for the gaps between outer and inner tie rods on both sides they are equal now when steering shaft mark isn't looking straight up. I think somebody turned steering shaft around steering machine in one bolt+ clamp joint. And I was trying to ask if this non centered shaft will affect somehow the number of steering wheel turns from center to R lock and L lock and make any harm to steering machine. Don't want to dissassemble this joint.
clanceman427 wrote:Make sure your settings match your tire type.  If you have radial tires use the radial alignment settings.  Bias ply tires were still standard back then but radial tires were optional.  They behave very differently and thus have very different alignment specs for the front suspension.
Understood, thank you, of coarse modern radial.
chevellelaguna wrote:As far as the caster camber shimming issue is concerned you may need an offset upper cross shaft. I had issues with aligning my front suspension, same as you with too many shims needed on one side of the cross shaft, no one made offset shafts at the time. I just made my own alignment shims out of 1/2 steel plate, so I wouldn't have to mess with slipping in six or seven shims. I'm pretty sure I had to replace at least two of the bolts as well because they weren't long enough to have the nut tightened down far enough, with the thicker shim pack in place. Offset cross shafts would have solved my issues, but it drives and handles so well and doesn't wear tire that I don't think I'll ever really mess with it again. It tracks straight, comes out of hard corners and centeres itself, isn't "darty". Not much steering input is required.
Don't forget the rotational torque on a rear wheel drive car unloads the front suspension, that changes the camber on the drivers side and in turn shoves the passenger suspension down. The really old school alignment guys take that into consideration also the crown in the road can be slightly compensated for, on one side, as well as full tank of gas, just driver no passenger weight etc.
Toe should be as close to zero as you can get it on our cars, toe-in up to 1/16" per side is acceptable. That's waaaay better than factory specs some of which I've seen were 1/4" per side!
It will be great to see your or somebody's suspension setting's printed.
Ok I can win a little more camber turning the cross shaft 180*. But I can't even realize how can I make +5* caster on stock suspension...Even when I made highest degrees of caster now without any camber cross shaft has very big angle according to frame surface. If doing more caster cross shaft will have very poor contact with shims...it must be inclined steel plates not shims...


So it will be very interesting for me of how you guys got your alignment specs on stock suspension, especially of those who drives cars on any competitions, like RTTC as I know.
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Re: Poor 74 front suspension alignment

Post by Hillbilly on Mon Sep 05, 2016 1:02 pm

I was hoping using the Moog offset shafts I could get more adjustment before the bolt runs out.

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Re: Poor 74 front suspension alignment

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