Randy 71

Vetters,
I would like the experienced guys to check the tolerences out. Looks like I have a little work to do. Alignment Tech said nothing to worry about. He couldn't get the left rear bolt lose and could not get the right front camber right (said he took the shims out and still would not get withiin tolerences



If the image is to small go to my web page bottom right side.

http://temp.corvetteforum.net/c3/randy_71


Thanks Randy


[Modified by Randy 71, 7:30 PM 3/16/2004]

norvalwilhelm

He was trying for positive camber. That is what the specs use to call for. Now the trend is to negative camber and that can easily be set. I would have set the right positive camber to negative and matched it to the existing negative camber.
It is more important to be equal side to side then exact spec settings.

norvalwilhelm

Looking again, Leave the left side alone and make the right camber negative and add .3 caster to equal the left. That is easily done with shims and left must equal right side.

norvalwilhelm

Looking at the rear I think the camber is high at over 1 negative and if you have wide tires cause the inside to wearout.
Use heat and free the bolt or get new adjustable struts.

Randy 71

norval, Looks like both the rear CAMBER are within specs. Looks like both rear TOE is what is out.

I am really concered about the left front Camber. If you remove the shims like he did then why would it not align the left CAMBER. Any ideas how to correct this?

Doesn't neg camber cause the tires to wear on the insides. That was my problem on the front. My tires in the rear were wearing perfectly. The TECH said my car was crabbing donw the road slightly prior to the alignment.


[Modified by Randy 71, 8:03 PM 3/16/2004]

norvalwilhelm

am really concered about the left front Camber. If you remove the shims like he did then why would it not align the left CAMBER. Any ideas how to correct this?

Positive camber is created by removing the shims and moving the A arm out. He removed all the shims and still the A arm did not move out enough. But today we like negative camber so while your left setting is not within specs it is more performance oriented. He could if you asked added shims to the right side to create an equal negative camber on the right and at the same time .3 more caster to again equal the left.
While this would have created out of specs alignment you would have the desired negative camber and equal caster.
For rear toe removing shims in the trailing arm is asking too much of the alignment guy. It could take hours/days to free up this bolt and shims.
You do the unsticking for him. This is a major headache of a job.
Back to the front they sell offset cross shafts with 1/4 inch more positve camber in it for just such problems as this. A car that is getting old might sag a bit and this makes camber adjustment impossible.
If it was me I would go with my first idea of leaving the left alone, it is a desirable setting and make the right with just the addition of a few shims equal exactly the left.
The rear is a whole other problem.
We are now using radial tires and prefer different setting but the left must equal the right and forget the idea of crown in the road so make the settings exactly equal

Randy 71

some very excellent points. I wish I had that info when he was talking to me about it. Seemed very sincere about trying to align it with a stuck rear bolt and a left front that would not get into specs.

He didn't mention off set shafts, thats sounds like what I need to do. What does 1/4 pos camber equate to in degrees? Will this get me within specs up front? He did ask what kind of rebuild parts I used in the rebuild, after market or GM?

The whole reason I wanted the alignment with specs was that my front tires were wearing on the inside. With neg camber am I going to have the same problem.?

What would be the ideal specs for alignment be these days?

norvalwilhelm

Tomporrow at work I could give you part numbers for the offset cross shafts. 1/4 inch will give you about 1/2 degree more positive.
I made my own shafts, I made a series of them for all situations.
This is a picture of one compared to a stock unit.
Double click on picture to enlarge


These are homemade but bought ones run $65. CDN each.

Randy 71

You have been a great help throughout this rebuil process. Could the left front been off because my gas was sitting empty. Tech did mention that with my 250 lbs on the drivers side that would help even it out up front, what do you think?

Just tocheck again........to much neg camber causes front tires to wear on the inside and to much positive would make the wear on the outside?


[Modified by Randy 71, 8:47 PM 3/16/2004]

norvalwilhelm

Gas was sitting empty?? I doon't see how that affected the left front camber.
I did run negative .75 camber last year without a problem but this year I am running ZERO 0 camber and positive 4 caster.
I am going to try running the tires front and back straight up. My 305 tires are wide and I want the foot print flat on the ground.
This could change any afternoon when I am in the mood.
Get a good qauge and set your own caster/camber. Cost about $132.
Double click to enlarge

CF6873

Just tocheck again........to much neg camber causes front tires to wear on the inside and to much positive would make the wear on the outside?

As someone said on this forum a few years ago. " To remember positive vs negative camber think of a woman lying on her back with her knees in the air." Positive out, negative in.

Craig :hurray:

LiveandLetDrive

Woh! Did he give you 1/2" of postitive toe in the front? And you would have already had .3 If I'm misreading that, you're fine, but toe out is a bad thing! I had 1/2" of toe out on the front, and it was barely driveable, darted and pulled very strongly. Also wore out the inside of my tires, as they were being drug down the road sideways pretty much. <.5* negative camber should have too much of an affect on tire wear, see http://www.vbandp.com for their recommendations.

What kindof tires are you running?

-Chris

Randy 71

235-60-15

lostpatrolman

Norval, that guage tells you your camber/caster, but how do you tell toe in/toe out? Where do you get the equiptment neccessary to align the car yourself?

LiveandLetDrive

He built his own toe gauge, which measures each side independantly, uses a dial indicator. There are some you can buy but the ones I've seen seem to only measure total toe.

-Chris

norvalwilhelm

Norval, that guage tells you your camber/caster, but how do you tell toe in/toe out? Where do you get the equiptment neccessary to align the car yourself?

Your right that reads caster/camber but I also made a toe gauge which is nothing more then a rod, a set of stands and pointers. Very easy to make. I also use a lazer level to project front to back and back to front.

norvalwilhelm

He built his own toe gauge, which measures each side independantly, uses a dial indicator. There are some you can buy but the ones I've seen seem to only measure total toe.

RUXperienced that gauge is for measuring toe change or bump steer. It is not used while setting normal toe. If I suspect a wheel changing toe while traveling through it's full range I bolt the aluminum plate to that wheel and check to change, not toe setting.
The easiest way to set toe at home is 2 aluminum plates about 28 or 30 inches and 12 inches high. Place then against either wheel and with a tape measure measure the back and front readings. This is how the stock car guys do it. I use my homemade gauge but have the plates also for backup.

American Boy

You're right about that but toe out will wear the tire on the inside too. As Norval said, you should get the alignement shop to get the front right to match the left side. The rear is close enhough but you could correct it too(new bushing...PIA).

Stephan

norvalwilhelm

Cross shafts with 1/4 inch more camber built in.
Part numbers for 63-79 vettes
McQuay-Norris FA1194
TRW 13166B

I ordered a pair of McQuay NOrris and they were in stock for $65.CDN each.

zwede

The front crossmember is sagging a bit, which is why you can't get positive camber. I'd recommend you closely inspect the frame for cracks, just to be on the safe side.

Also recommend you get a spreader bar to straighten it out some but mostly to prevent further sagging. Think of the front crossmember as a "U". The upper A-arms are pressing the top of the U together. After so many years the metal weakens and the top of the U is now closer together than when it was new. The spreader bar stabilizes this weak area.

Now for the alignment: -0.6 camber is more than I'd shoot for on a street car. I would NOT align it to factory camber or you will wear out the outside edge of the tire for sure. I like -0.2 to -0.3. Both sides must be equal. You have 1 degree cross camber which is no good.

Caster: Get as much as possible. More is better for Caster. If you can get 3 degrees, that's great. Otherwise 2.5 will have to do.

You have alot of toe-in. Yes, it's within spec, but the spec sucks for our cars. I won't run more than 0.125 (1/8") toe-in. This is for the front and rear.

Rear you have too much neg camber. Go for -0.5 dgr for even wear and good handling on the street.

You also have toe-out on the rear which is a no-no. You need to get those shims loose and have him set about 1/8" toe-in in the rear.

With these fixes you will notice significantly better performance compared to now and even tire-wear.