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I have no idea why you wouldn't want the max caster as you can get since the two main benefits of that are: Improved straight-line stability at speed and Improved vehicle handling and cornering performance. Something else is way out if he ran the same tires before with settings before the alignment. Something changed dramatically.
I have no idea why you wouldn't want the max caster as you can get since the two main benefits of that are: Improved straight-line stability at speed and Improved vehicle handling and cornering performance. Something else is way out if he ran the same tires before with settings before the alignment. Something changed dramatically.
we don't know what the before alignment was back in 2022 before the problem occurred , he never posted it. The before alignment now is extreme 5+. I know all the benefits of extra caster but in this case it is causing an issue.
we don't know what the before alignment was back in 2022 before the problem occurred , he never posted it. The before alignment now is extreme 5+. I know all the benefits of extra caster but in this case it is causing an issue.
Thanks for all the feedback everyone. The last time the car was aligned back in 2011 or 2012 after I got it by Goodyear. I do not have those specs and the Goodyear location that did the alignment does not exist anymore. I am blown away by this. These shops say "oh yea, oh yea, we can do it" and have nerve to have crap like "alignment specialist...." in their name then they screw crap up. I just do not want that tire to freaking crack the front wheel well lip. Luckily, I do not drive the car much and rarely have to make real tight right turns. Please bear with me. I will take pics and post them by the weekend.
The caster both before and after is red because it's too much caster not too little.
Did they have a problem trying to set caster to + 2.75 which is the maximum number.
Do you have bent control arms?
What???
Are you for real?
The reason we install offset and slotted A arm shafts, aftermarket upper A arms, etc. Is to get AS MUCH CASTOR as we can !!
At 2.75. With Manual steering you might be just OK.
with power steering, well over 4 degrees is minimum for high speed stability and 5.5 degrees is better.
Many shoot for 6.
Yes I know, the original factory manual says 2.75.
And everyone in the know in the way of suspension and handling on these cars disagrees.
perhaps Google performance alignment specs, C3 Corvette.
So , let's look at this. He changed ball joints and tie rod ends as well as A arm bushings. So, he did the right thing and took it in for a alignment.
when he took it to the shop. He had no rubbing.
They did a before reading. Common in many shops to record how the car was when it came in.
Keeping in mind he had no rubbing!
His original caster specs according to the shop were, 5.2 degrees left and 5.4 degrees right. Which Are EXCELLENT, well to most of us anyway.
But these specs beg to question, if his car has factory A arms and shafts. How is this even possible?
Then they align his car and come up with caster specs of 3.4 and 4.2. Which is certainly worse in more ways than one. The original difference of .2 degree. Is acceptable. The new difference is .8 degrees, almost a full degree difference, this is absolutely NOT acceptable. They record they reduced caster, yet his wheel is now closer to the front of the wheel well opening!
THIS CAN NOT BE CORRECT!
If they reduced his caster, the wheel should be further to the rear!
I propose that the shop has defective equipment or a defective tech doing the work!
Over the years the topic of "What size tires do you run" has come up time and again. I believe that the 255/60-15 has to be the most common size tire run on these cars! The only answer here is this alignment shop stuffed up the OP's car!
And to anyone telling me to pull caster back out of my car to get it back to factory spec, so I can again have ultra light steering at speed. I can assure you that's never going to happen!
So , let's look at this. He changed ball joints and tie rod ends as well as A arm bushings. So, he did the right thing and took it in for a alignment.
when he took it to the shop. He had no rubbing.
They did a before reading. Common in many shops to record how the car was when it came in.
Keeping in mind he had no rubbing!
His original caster specs according to the shop were, 5.2 degrees left and 5.4 degrees right. Which Are EXCELLENT, well to most of us anyway.
But these specs beg to question, if his car has factory A arms and shafts. How is this even possible?
Then they align his car and come up with caster specs of 3.4 and 4.2. Which is certainly worse in more ways than one. The original difference of .2 degree. Is acceptable. The new difference is .8 degrees, almost a full degree difference, this is absolutely NOT acceptable. They record they reduced caster, yet his wheel is now closer to the front of the wheel well opening!
THIS CAN NOT BE CORRECT!
If they reduced his caster, the wheel should be further to the rear!
I propose that the shop has defective equipment or a defective tech doing the work!
Over the years the topic of "What size tires do you run" has come up time and again. I believe that the 255/60-15 has to be the most common size tire run on these cars! The only answer here is this alignment shop stuffed up the OP's car!
And to anyone telling me to pull caster back out of my car to get it back to factory spec, so I can again have ultra light steering at speed. I can assure you that's never going to happen!
One clarification here, the caster specs of 3.4 and 4.2 are from the 2023 alignment. The car did not rub before the 2022 alignment or after I put the changed ball joints and tie rod ends as well as A arm bushings in 2022. It started rubbing after I took it for alignment in 2022 and continues to rub after the 2023 alignment. What you are quoting as the "original specs" are specs from the 2022 alignment and it rubbed with the 5.2 caster on the driver side. That's why I went to a different alignment shop in 2023 and now have 3.4 caster and it still rubs on the driver side.
Increasing positive caster angle will move the upper ball joint aft, moving the wheel towards the rear of the wheel well.
You're saying the alignment shop decreased the caster angle, but somehow moved the wheel aft? That makes no sense, unless they reversed the caster angle measurement convention. Looking forward to seeing some photos! Take the wheel off if you can.
Agreed, good photos of upper and lower A arms.
Something is clearly not right here. Above, below, looking at the upper and lower attachment points, etc.
This size wheel should not be rubbing.
Agreed, good photos of upper and lower A arms.
Something is clearly not right here. Above, below, looking at the upper and lower attachment points, etc.
This size wheel should not be rubbing.
Agreed - It never rubbed before the 2022 or 2023 crap alignments. Photos coming by the weekend. Hoping to get to the bottom of it. Thanks everyone.
Last edited by hgoodwiniii; 03-28-2024 at 09:27 AM.
Adding 2* of positive camber moves the upper ball joint roughly 1/4" rearward.
Since the lower ball joint stayed still, this only moves the tire roughly 1/8" rearward.
That little bit is not causing your problem I think.
I believe it is possible to reverse the upper a-arms. And IIRC the B/J is staggered to the rear. That could easily be enough to do it.
Look at the upper ball joint mounting surface, it should be roughly horizontal, even tho the the rear of the a-arm is tilted down.
This is my passenger side arm. I marked the arrow as close as I could to the middle. The ball joint is definately displaced rearward. The Ball-joint mounting surface is tilted 10* down to the front here. When the arm is mounted the arm is 10* down to the rear, and then that surface is flat. Yours could be reversed. giving you a major forward shift of your ball-joint, and tire. And reducing your pos caster.
Also your new alignment specs are horrible. It was better before. You should not have positive camber in front. It looks like they may have tried to use ancient GM specs, which are for bias ply tires.
These are the ones you should use, from Van Steel. These are well tested specs for our cars, and are for modern radial tires. I suggest the Advanced Street specs. 4-5* caster is excellent, if you can get it.
These toe-in measurements are in inches. 1/8" toe-in = 0.29 degrees. Most machines use degrees now. Getting that rear toe-in setting correct is very important, or it will handle squirrely.
Adding 2* of positive camber moves the upper ball joint roughly 1/4" rearward.
Since the lower ball joint stayed still, this only moves the tire roughly 1/8" rearward.
That little bit is not causing your problem I think.
I believe it is possible to reverse the upper a-arms. And IIRC the B/J is staggered to the rear. That could easily be enough to do it.
I don't think you can. I just tried, and the arm hits the front of the inner fender notch.
I also noticed that the front edge of my 79's wheel wells have been trimmed, presumably at the factory.
Well that leaves his alignment.
Both changes they made move the tire closer to the fender.
1* pos more camber moves tire out.
.3* less pos caster moves the tire forward.
It could be the combination of the two causing it then.
If you look at the photo I put up of my front wheel/fender. Gezz that's a pretty good gap from tire to forward fender inner edge. My 77 has the same body as his 76.
Just looks like more going on here than a minor alignment adjustment.
03-27-2024, 08:09 PM
