[RUQWIKR]

The holes through the rear cradle for the alignment pins are just behind the rear bushings. You'll see a hold through both lower and top side of the cradle and a mating hole in the body for the cradle alignment pins to go through. Mine cradle has not been out yet or moved. One day, I'll finally install my solid bushings I've had up on the shelf (forever).

[Msquared]

Originally Posted by TrackClub

On the LR, the tech said he could only get max 1.4 camber even without any toe adjustments.

Okay, a misaligned cradle could not account for that problem, because none of the links attach to the body - they only attach to the cradle. So the cradle and suspension is a complete unit unto itself, and you can remove it from the car completely and set the camber or total toe:



That pic has all of rear suspension still attached to the cradle. The only things that touch the unibody besides the four cradle mounts are the tops of the shocks and coil springs, but those don't do anything to locate the wheel and therefore have no say in alignment. The front suspension is different, because it has struts that attach to the unibody at the strut towers. So if you shift the front subframe right or left you affect camber on each side. But the rear isn't like that.

And when he got the 1.4, the toe out was at close to 0.3 and he could not budge it in AT ALL.

This is the part that a crabbed cradle could cause. Look at this extremely crude drawing of a rear suspension:



Here, the center black square is the cradle and the outer black rectangles are the tires or hubs. The red links are lateral suspension links, and the yellow links are the toe links. When the cradle is nice and square with the thrust centerline of the car, the tires aim straight ahead and the toe link lengths are equal to each other. When it's skewed off of the thrust line (second example), the tires can still be aimed exactly straight ahead (zero total toe relative to each other) but the left toe link has to be a lot longer than the right one to achieve that. Our cars effectively run out of toe link length when we dial in lots of negative camber, so this could explain why the right side can easily be at zero toe but the left side cannot. I hope this makes sense.

[LESS1]

Sorry to hear you are having issues and hopefully it is an easy fix. Not implying this is the issue but I believe Chevy had a problem with toe links cracking back in 2016. Any idea if the Techs actually inspected the toe links? Or did they just focus on the job at hand? It's very easy to miss these small details. Also once you sort this out have them do a dynamic alingment with you in the car and a 1/2 tank of petrol.

[TrackClub]

Originally Posted by Msquared

Okay, a misaligned cradle could not account for that problem, because none of the links attach to the body - they only attach to the cradle. So the cradle and suspension is a complete unit unto itself, and you can remove it from the car completely and set the camber or total toe:

Attachment 1039211

That pic has all of rear suspension still attached to the cradle. The only things that touch the unibody besides the four cradle mounts are the tops of the shocks and coil springs, but those don't do anything to locate the wheel and therefore have no say in alignment. The front suspension is different, because it has struts that attach to the unibody at the strut towers. So if you shift the front subframe right or left you affect camber on each side. But the rear isn't like that.


This is the part that a crabbed cradle could cause. Look at this extremely crude drawing of a rear suspension:

Attachment 1039217

Here, the center black square is the cradle and the outer black rectangles are the tires or hubs. The red links are lateral suspension links, and the yellow links are the toe links. When the cradle is nice and square with the thrust centerline of the car, the tires aim straight ahead and the toe link lengths are equal to each other. When it's skewed off of the thrust line (second example), the tires can still be aimed exactly straight ahead (zero total toe relative to each other) but the left toe link has to be a lot longer than the right one to achieve that. Our cars effectively run out of toe link length when we dial in lots of negative camber, so this could explain why the right side can easily be at zero toe but the left side cannot. I hope this makes sense.

Excellent explanation, makes total sense to me: thank you so much, including the drawing!

The tech surely runs out of the toe link length on the RL, so a crabbed cradle could indeed be an issue. But:

Given he can only dial in about 1.4 camber to start with, any idea what condition could cause THAT issue?
Is there a related test that could be done on the RR to help with that determination, perhaps?
Or some other checks, or measurements that could possibly help in finding a root cause?

Unless GM decides to send their top suspension corporate tech to check my car, i am afraid i may have to provide as many possible suggestions and tests for the dealer techs as possible. As much as they may be good techs per se, it is clear, that they have never run into such an issue before. And i am unsure to what extent they understand inter relationships of different parts et al.

I really need to get them to the root cause, as if this is overly complex (as in faulty assembly of sorts), i dont want to end up with half a solution and an ill handling car "by design".

Again, much appreciate all the details, explanations and the illustration. Simply brilliant! Cheers!

[Msquared]

Originally Posted by TrackClub

The tech surely runs out of the toe link length on the RL, so a crabbed cradle could indeed be an issue. But:

Given he can only dial in about 1.4 camber to start with, any idea what condition could cause THAT issue?
Is there a related test that could be done on the RR to help with that determination, perhaps?
Or some other checks, or measurements that could possibly help in finding a root cause?

It's going to have to be something related to a link being bent or the wrong length, or a tab (pivot point) being in the wrong location on the cradle. As I think about it, if the upper lateral link were too long (or its mount too far out on the cradle), it would cause both issues: making it impossible to get the full amount of negative camber and also impossible to get the toe link out far enough. Only way to check this that I can think of is careful measurement and comparison of each link and mounting point to its counterpart on the other side.

[TrackClub]

Originally Posted by LESS1

Sorry to hear you are having issues and hopefully it is an easy fix. Not implying this is the issue but I believe Chevy had a problem with toe links cracking back in 2016. Any idea if the Techs actually inspected the toe links? Or did they just focus on the job at hand? It's very easy to miss these small details. Also once you sort this out have them do a dynamic alingment with you in the car and a 1/2 tank of petrol.

Thank you! I am fairly sure they just focused on a job at hand, but i could tell they felt stumped with LR.
The last tech spent a good hr or so, just trying to dial the LR (i told him up front it was an issue, based on the first alignment). While RR took a few mins. He was extremely apologetic and i think he did his best, considering the circumstances. He backed out the camber to ensure i had even toe in, even if i ended up with 1.1 and 1.6 (L/R).
But he alerted me to the fact he could not fix it.
The first tech (different shop) sent me home with 1.4 and 0.3 toe *out*, which was completely unacceptable.

[TrackClub]

Originally Posted by Msquared

It's going to have to be something related to a link being bent or the wrong length, or a tab (pivot point) being in the wrong location on the cradle. As I think about it, if the upper lateral link were too long (or its mount too far out on the cradle), it would cause both issues: making it impossible to get the full amount of negative camber and also impossible to get the toe link out far enough. Only way to check this that I can think of is careful measurement and comparison of each link and mounting point to its counterpart on the other side.

Got it - thank you!

[TrackClub]

Originally Posted by Msquared

It's going to have to be something related to a link being bent or the wrong length, or a tab (pivot point) being in the wrong location on the cradle. As I think about it, if the upper lateral link were too long (or its mount too far out on the cradle), it would cause both issues: making it impossible to get the full amount of negative camber and also impossible to get the toe link out far enough. Only way to check this that I can think of is careful measurement and comparison of each link and mounting point to its counterpart on the other side.

One more question if i may: would the lack of camber condition be at all possible due to an incorrect relationship between the cradle and subframe?
In other words, could the subframe in any way play a role? Or, is that out of the question? Thanks!

[cdb95z28]

2 different shops and 2 different techs performing them, correct?
At the rear, adjusting the camber will change the toe.

But, and I am not certain, but on a Gen6, adjusting the toe may not have as large of an affect on the camber as the Gen5 Camaros do.

If it does, then giving it more toe in will change the camber to more negative.

OP, can you take a current picture of the LR rear adjustment eccentrics?
Like this:

[TrackClub]

Originally Posted by cdb95z28

2 different shops and 2 different techs performing them, correct?
At the rear, adjusting the camber will change the toe.

But, and I am not certain, but on a Gen6, adjusting the toe may not have as large of an affect on the camber as the Gen5 Camaros do.

If it does, then giving it more toe in will change the camber to more negative.

OP, can you take a current picture of the LR rear adjustment eccentrics?
Like this:
Attachment 1039242

Yep, 2 shops, 2 techs. The first one was the same guy who did my 17 and he nailed it perfectly the very first time according to my specs.

The second shop/tech (both GM dealers btw) has a Vette friendly rack and is much closer to me. Unfortunately, the dealer i bought the car from is equally close, but they dont have a proper rack. However, the co owner whom i know, has promised to escalate this to GM corporate.

I will snap a pic a bit later this am. Cheers!

[Msquared]

Originally Posted by TrackClub

One more question if i may: would the lack of camber condition be at all possible due to an incorrect relationship between the cradle and subframe?
In other words, could the subframe in any way play a role? Or, is that out of the question? Thanks!

Let's clarify terminology. "Subframe" and "cradle" are the same thing. It's the big stamped piece of black metal that all the suspension links, swaybar, springs, and shocks mount to, and in turn it bolts to the unibody (or "frame") of the car using four big bolts with bushings. Here's a pic of the cradle/subframe with nothing bolted to it:



You can pick it out in the picture of the "fully loaded" cradle I posted a few posts back. So the cradle and unibody is all there is back there. I don't see any way that a misalignment between the cradle and unibody could cause a loss of camber range.

[TrackClub]

Originally Posted by Msquared

Let's clarify terminology. "Subframe" and "cradle" are the same thing. It's the big stamped piece of black metal that all the suspension links, swaybar, springs, and shocks mount to, and in turn it bolts to the unibody (or "frame") of the car using four big bolts with bushings. Here's a pic of the cradle/subframe with nothing bolted to it:

Attachment 1039247

You can pick it out in the picture of the "fully loaded" cradle I posted a few posts back. So the cradle and unibody is all there is back there. I don't see any way that a misalignment between the cradle and unibody could cause a loss of camber range.

Got it thank you! Likely a redundant question, but just to make perfectly certain: understanding that a relationship between a cradle and unibody could not cause lack of camber, could an improperly installed/twisted/damaged/whatever unibody have any effect on camber?

PS Sorry no pix today as i had to be away all day. Will post some tomorrow. Cheers!

[Msquared]

Originally Posted by TrackClub

Got it thank you! Likely a redundant question, but just to make perfectly certain: understanding that a relationship between a cradle and unibody could not cause lack of camber, could an improperly installed/twisted/damaged/whatever unibody have any effect on camber?

Well, the unibody is basically the foundation for the rest of the car, so on the assembly line they attach parts to it, not the other way around. But the short answer is no, I can't think of a way it could be damaged enough to cause the loss of basically a degree or more of negative camber.

[TrackClub]

Originally Posted by Msquared

Well, the unibody is basically the foundation for the rest of the car, so on the assembly line they attach parts to it, not the other way around. But the short answer is no, I can't think of a way it could be damaged enough to cause the loss of basically a degree or more of negative camber.

Ok thx! So, hypothetically, if they replaced a whole cradle, my problem should go away.