[TrackClub]

Originally Posted by Stephen12ZL1

"eccentrics are the devil" according to the owner/developer of SPL parts. Consider some of the parts there which appear top notch. https://www.splparts.com/

Thx for the link: nice parts! But, i am gonna treat it as a warrany issue with 1st step being to determine what is wrong. Dont want a band aid solution if the rear end is crooked (possibly) due to improper assembly. I suspect this would cause quite an inbalance at a track...

[TrackClub]

Originally Posted by apexit53

we did our best to bend them back and it worked but it was never the same. Tried to get a dealer to warranty the sub frame but wouldn't.

You mean the balance was never the same?
Did ya get proper camber after fixing the bent bolts?
Thanks!

[Move_Over]

How certain are you that the alignment rack is 100% right? I had a similar issue at my favorite race shop (been doing my alignments for years) and it wound up their machine was way, way off. They had to have the hunter rep come in and calibrate the machine.

Worth looking into...

[apexit53]

Originally Posted by TrackClub

You mean the balance was never the same?
Did ya get proper camber after fixing the bent bolts?
Thanks!

No, more like the adjustments were never the same.

[Msquared]

Originally Posted by TrackClub

Thanks! Great tip to measure everything. My biggest worry is things were not welded properly. If so GM will own this car as i suspect a fix would be difficult?
Not mech inclined here, so simply dont know what this would entail...Cheers!

Well..."difficult" is in the eye of the beholder. The whole subframe cradle comes out as a unit. People sell them on eBay, so it isn't rocket surgery. It would take time, because once the whole thing is pulled, all the links plus diff and halfshafts and brakes (etc.) would have to be transferred over to a new subframe. Then it would all get installed with the new subframe. That's the kind of thing that a lot of us would tackle, but I'm not sure about the dealership. I suspect that the bigger challenge will be getting GM to warranty it. Their fallback will be that you can get alignment to fall within normal specs, so there's no malfunction. OTOH, if you're lucky then it will just be a back toe link.

As for the accuracy of the alignment rig, TrackClub indicated that it was checked in two different shops. And yes, eccentric alignment adjusters are indeed the devil, or at least the spawn of the devil. Slippage (i.e. not holding their alignment) is the biggest problem.

[RUQWIKR]

Originally Posted by Move_Over

How certain are you that the alignment rack is 100% right? I had a similar issue at my favorite race shop (been doing my alignments for years) and it wound up their machine was way, way off. They had to have the hunter rep come in and calibrate the machine.

Worth looking into...

Had that with a RF "issue" with it being a rack out of whack. TrackClub, on your rear cradle, did your dealer stick the cradle alignment pins through the cradle into the body to make sure it is aligned?

[TrackClub]

Originally Posted by Msquared

Well..."difficult" is in the eye of the beholder. The whole subframe cradle comes out as a unit. People sell them on eBay, so it isn't rocket surgery. It would take time, because once the whole thing is pulled, all the links plus diff and halfshafts and brakes (etc.) would have to be transferred over to a new subframe. Then it would all get installed with the new subframe. That's the kind of thing that a lot of us would tackle, but I'm not sure about the dealership. I suspect that the bigger challenge will be getting GM to warranty it. Their fallback will be that you can get alignment to fall within normal specs, so there's no malfunction. OTOH, if you're lucky then it will just be a back toe link.

As for the accuracy of the alignment rig, TrackClub indicated that it was checked in two different shops. And yes, eccentric alignment adjusters are indeed the devil, or at least the spawn of the devil. Slippage (i.e. not holding their alignment) is the biggest problem.

Thanks for the info!

Indeed the feedback from 2 shops has been the same.
They can't even get to 1.5 camber wise. At 1.4 the toe is at almost 0.3 OUT and they cant bring it in never mind getting anything in toe IN position.

Had a meeting today, with the tech that spent 2.5 hrs on it yesterday (their best apparently) and the service manager. He did try to suggest warrany wont apply as 1.1 camber is achievable and that is "good enuf". However, i pointed out this is a 1LE model with $8.5k track option and hence it must achieve what GM officially specs for alignment wise right in the High Performance Supplement manual. So, they will take it up with a regional manager, to spend some time under warranty to see if they can identify the issue.

We shall see how it goes...Cheers!

PS To say i am aboslutely pissed off is an understatement, as i have stopped the break in process now and this issue can casue me to lose a whole season (shortened as it is already).

[Msquared]

It's worth noting that the 2019 Camaro Models Track Preparation Guide specifies rear camber for an SS 1LE at "-1.5 plus or minus 0.15" for "optimized road course usage." This is the same as called for in the 2020 Chevrolet Camaro High Performance Owners Manual Supplement. So there are multiple publications that cite camber numbers you can't reach.

[TrackClub]

Originally Posted by RUQWIKR

Had that with a RF "issue" with it being a rack out of whack. TrackClub, on your rear cradle, did your dealer stick the cradle alignment pins through the cradle into the body to make sure it is aligned?

Dont know if they did or not.
The car was on 2 different racks in 2 days. Same result. But who knows? Another item to add to the list
Thank you!

[TrackClub]

Originally Posted by Msquared

It's worth noting that the 2019 Camaro Models Track Preparation Guide specifies rear camber for an SS 1LE at "-1.5 plus or minus 0.15" for "optimized road course usage." This is the same as called for in the 2020 Chevrolet Camaro High Performance Owners Manual Supplement. So there are multiple publications that cite camber numbers you can't reach.

Yes indeed! That's exactly what i had quoted them as part of official GM printed material re specs.

[Msquared]

Originally Posted by RUQWIKR

Had that with a RF "issue" with it being a rack out of whack. TrackClub, on your rear cradle, did your dealer stick the cradle alignment pins through the cradle into the body to make sure it is aligned?

Earlier I wrote that this can't cause the issue because all the suspension links including the toe link all attach to the cradle rather than the body/unibody. But I think I was wrong.

If that cradle were crabbed at 1-deg to the left, then to get proper thrust alignment you'd need an extra degree of left toe adjustment available. That extra degree isn't available on our cars when we try to dial in max negative camber. The test for this (aside from the alignment pins RUQWIKR mentioned) would be to see if you can get way more than -1.6 camber on the RR while still keeping toe in spec. Or put another way, if you ignore thrust alignment and only focus on total toe on the rear, can you get -1.6 on both sides and keep total toe around zero (albeit with the thrust angle being off)? If so, and if the links and tabs are straight and measure correctly on the cradle, then the cradle is crabbed away from the thrust centerline.

Keep in mind that this isn't about whether the cradle is shifted sideways or fore/aft too much, but rather one of whether it's turned a bit off the thrust line. If that's the case, then the fix might be as simple as loosening the cradle bolts, setting the cradle straight ahead, and tightening the bolts.

[TrackClub]

Originally Posted by Msquared

Earlier I wrote that this can't cause the issue because all the suspension links including the toe link all attach to the cradle rather than the body/unibody. But I think I was wrong.

If that cradle were crabbed at 1-deg to the left, then to get proper thrust alignment you'd need an extra degree of left toe adjustment available. That extra degree isn't available on our cars when we try to dial in max negative camber. The test for this (aside from the alignment pins RUQWIKR mentioned) would be to see if you can get way more than -1.6 camber on the RR while still keeping toe in spec. Or put another way, if you ignore thrust alignment and only focus on total toe on the rear, can you get -1.6 on both sides and keep total toe around zero (albeit with the thrust angle being off)? If so, and if the links and tabs are straight and measure correctly on the cradle, then the cradle is crabbed away from the thrust centerline.

Keep in mind that this isn't about whether the cradle is shifted sideways or fore/aft too much, but rather one of whether it's turned a bit off the thrust line. If that's the case, then the fix might be as simple as loosening the cradle bolts, setting the cradle straight ahead, and tightening the bolts.

Thanks Matt - another for the list

Unfortunately, i am not at all familiar with these parts, so you guys will have to spoon feed me and i greatly appreciate it in advance!

At this point, the didnt do any experimenting at the dealer, apart from trying to get me an alignment according to my specs. As such, i dont know how much more camber they could have achieved on RR. All they told me that side was super easy to get 1.6 and 0.05 toe in.

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

Anyhow, that's all I know at this point. Hopefully GM will authorize some time to investigate/experiment under warranty. If and when that happens, i will pass all the suggestions to them.

Please keep them coming. Thank you!

[DaveC113]

Sounds like the rear cradle/subframe isn't in alignment to me. I hope it's as easy as loosening and retightening some bolts... Good luck!

[TrackClub]

Originally Posted by DaveC113

Sounds like the rear cradle/subframe isn't in alignment to me. I hope it's as easy as loosening and retightening some bolts... Good luck!

Appreciate it - thank you Dave!