Hi, Rebuilt my front end with new springs and bushings here. 1979
https://www.corvetteforum.com/forums...rs-method.html


That’s quite a spread for passing inspection

I find the service manual that’s a very good job of explaining things

Excellent app and free I am amazed at how repeatable an accurate it is I almost bought some more junk off Amazon specifically for this task but I find the iPad to be large and more consistent than your phone



I have researched a lot about how to measure camber caster and toe before I do a parallelogram for toe I am finding a way to check camber first and I found a very excellent app and accuracy seems to be spot on the iPad for finding the degree of angle.
i use a very straight piece of wood oak and cut it exactly to fit the inside of the wheel lip and it is perfectly straight and I hold my iPad on the edge and it gives me a very consistent repeatable read out of degree.
It also can be zeroed out on the concrete to adjust for any unlevelness.
so on the driver side I have positive 0.6° camber and on the passenger side I have positive 1.5° camber.
Theoretically according to warranty or a customer service I’m OK barely I’d like to get it back to specifications for a resetting alignment. I’m not going to mess with the driver side camber but I do want to adjust my passenger side camber so my question is what shim size is a guess to get my camber reduced by 3/4 of a degree? And where do people normally buy their shims that does the chain stores carry shims?
thank you , here is a fun chart from 1979 service manual

 

I use an iPhone app called Tremec Toolbox. It's good to a 10th of a degree and is repeatable with an old piece of granite counter top as a "straight edge". For 1.2 degrees I would try a 1/16" shim on front and rear bolts depending on what you want to end up with. My floor in this stall is level.

 

Ya i seen your post in researching which gave me the idea..
not sure that app has zero out for non level but did download it...
amazing how technology in these devices can be used..
of course my shim passenger side is buried with ac etc...do you know how
what size shim changes degrees?

 

I was having a beer with a friend who owns a GM dealership here and was telling him about the Tremec driveline angle finder. He thought I was nuts so off we go on a Sunday afternoon to his shop with the 69 and he gets his alignment machine running. He took measurements then tried the Tremec app and they were the same. His is better than a 10th of a degree but as he said: "You know how much it cost me for this machine and yours is not only free, but it's on your phone??"
The app doesn't have zero out for an uneven floor but if you run a level or straight edge across the floor you can measure with the same app and compensate.
I can't remember the formula for degrees to inches on a stock 15" rim which is actually 16" lip to lip but you might google "alignment inches to degrees" or something like that.

 

Old racer's trick;
I leveled my garage floor with some Home Depot floor tiles under the tires. Two at Rt front, 1 at right rear. Keep them on the shelf.
Long aluminum square bar from there as well.

But I DO so like the phone app trick!

 

The only thing you have to watch out for is which iPhone you are using. The one in the pic is a 5 if I remember right and the right side edge is smooth so no problem. Later models might have a slightly protruding button on the right side which will throw things off so you just grind a little "button" notch at the center of your straight edge to compensate. That way you get an accurate measurement. I use that old "5" just for alignments.

 

yup, which is exactly why i love the ipad, flat side and long..pop board on floor ahead if tire, pop zero, go..
i researched 1/64 0.1 degree...estimate.. so...here is what i got from napa..will shoot for adding 3/4 degree

All napa had was 1/8 to 1/16 to 1/32..

 

My wife came out to the garage while I had my old "alignment" phone on the bench. "Why do you have a second phone? What's going on here?"
Then you unsuccessfully try to explain that....

 

ipad had bigger images too...and you can make calls ...so no suspicion 🤔

 

Those Napa shims are kind of wide on that inside taper but they will work. I prefer the narrower old GM type shims for more support surface behind the nut. Above is an original 1969 GM C3 shim and on the right is a Napa one. Not a big deal but the gap is a bit wide.

 

Yup agree meant to fit 14mm to 16mm..ours are 14..
I actually ground down new ones to look like old and easier to grab in tight space but ya got to make sure its in there..
ok installed 1/16 x2..
new readings after driving 10 feet back and 10 feet forward..
driver side 0.7 after driving a few miles 0.7
passenger side was 1.5 after 10 ft 1.2 after drive 1.2...

ugh..hate ripping that air cleaner out again...
drives ok..seems slightly pull to right as before..
go in with 1/8? Or add 1/8? So i have 3/8 total add? Seems like a lot

 

Yes, I think she's now sitting in the bedroom with it waiting for it to ring....

 

If the steering wheel is off center to the right or left that's one thing as it's controlled by equal tie rod adjustments but if it actually pulls to the right you have another problem that could be anything from a dragging caliper or centering of the power steering control valve. If just the alignment is off it shouldn't actually pull to one side with no input on the wheel.
You can tell if it's the PS control valve by lifting the front end an inch or two off the ground, start the car and see if the pressure is equal turning the steering wheel both ways or it might even turn to one side on it's own.

 

Ok
omg what a great day in central Indiana!!!
i got solid rubber in second gear with ac on!!!!!!!!!
stock l82 4m with duals..Ok back to camber....
installed 1/8 inch spacers removed 1/16
i used a vice and squeezed tangs together to hug shaft better and ground down like originals not so much for aesthetic bit tight spot under ac and easier to grab and align then tap in with screwdriver because the damn things fall if too loose..
ok
measurements right after adjustment, after 10 feet, after drive did NOT change..even after jousting bumper as manual says...maybe not so important for camber
drivers side 0.8° passenger side 0.9°
Steering wheel has always been perfectly straight and aligned even with a drifting to the right it no longer drift to the right and drive straight as an arrow and is beautiful.
So to answer the question of that I never could find how much **** do you put in to change the camber degrees the answer is about an 1/8 inch for 0.6 of a degree.
This thing handles great I can’t what it what a fantastic project rebuilding the front end and doing most everything yourself I’m not gonna take it into the alignment shop I don’t drive it that much certainly not a tremendous amount on the highway so I’m good to go. I appreciate the help CanadaGrant and motivation..
maybe check camber sometime not today!!

 

I believe you are measuring Camber, correct? And not caster?
Camber changes should not really make the car pull right or left. They do dramatically effect tire wear and cornering.
And you probably want them the same on both sides.

Now two different Caster readings are commonly used to make the car pull very slightly "left" so as to counteract the road surface "crown". The idea is the curved road tends to make your car drift right, and you want a little more caster in one side to try to make it climb the crest of the road, ultimately going "straight" when you let off the wheel.

I found it changed rather noticeably depending on how much "crown" the road had, and if you were in the right lane or the left lane, which have a different crown. So sometimes my car would drift right, sometimes left, and sometimes straight ahead. The inconsistency drove me crazy!. I especially didn't like it when it drifted left, into the oncoming lane of traffic!

So I always set my caster the same right and left, and let the loose nut behind the wheel do all the correcting. And at least my car tends to steer away from oncoming traffic.
*** the factory alignment settings!

You "tilt" the upper A-arm ball-joint toward the back of the car to get more caster. More shims in the back and less in the front.If you move a shim from front to back the camber "should" stay the same while the caster increases. The more caster you can run on these old C3s the more self-return there is to the steering and the less nervous it feels on the highway.Go for as much as you can get, but it is probably only 2 to 2.5 degrees which isn't much, but it's all you can get, without mechanical changes.

Update: So if it drives pretty "straight" I wouldn't even worry about the caster, nor take it to an alignment shop. You are doing a great job!
However, you always want to adjust the Toe as the last thing, and that one can have a big effect on tire wear.
All you need is 2 tape measures and 2 4 foot straight-edges.

 

What I just changed was the camber I was thinking about measuring the caster after studying on it for quite a while but I’m blown away that apparently the camber did in fact affect my car from slightly pulling to the right it wasn’t severe it was just noticeable that it would wanna wander to the right now it’s dead straight as far as the feeling of the steering going back to center it just feels a little tighter and it’s probably because of all the new parts I put on and the new bushings new ball joints new idler arm new bushings really rides nice oh and a new spring.
And I agree with you I am blown away how accurate the iPad is

 

Well I decided to do some toe-in measurements and look up and try the string method I also have a self leveling laser so I did them both and I use the Square on the floor for the string and the laser i use the calipers to see where the light hits and to my surprise once the string is set up and once the laser set up and I measure from as far front I can get on the frame underneath the door to as far back as I can get underneath the frame (while frame flat) as a point of reference for each side and the damn readings were almost identical for laser and string. So here’s my toe-in numbers I measured I did each side front and then just took the difference it appears that each side is one 16th of an inch toe-in and so I am going to assume somebody correct me if I’m wrong that I am running about 1/8 of an inch toe-in which according to the factory could probably use a little more but should be OK when I measure the rear toe-in and I had to measure it many times and the laser was probably the closest but the string in the laser were very close I’m going to say on the driver side I got about a 1/32 toe-in the passenger side I’m going to say a hair less than 1/32 toe-in when I’m going to assume that the last thing left is the caster
I want to go to the store to get some throwaway tiles I’m gonna give that a shot when I have time maybe next weekend and will report






Looks like i may be less than spec? Im about 1/32

 

Congratulations!
You just gave your car a more accurate alignment than many shops, especially the ones that are fast (too fast). And you didn't spend $200 or need a $10,000 machine. Just took a little longer. But it is very accurate.

Yes caster is a little more of a PITA, but whatever numbers you get, the main thing is to just make sure they are pretty close left & right.