Lower Control Arm - GM Redesign Status? - Camaro5 Chevy Camaro Forum / Camaro ZL1, SS and V6 Forums

tjd24 · 10-31-2011, 05:13 PM

I understand that the lower control arm was redesigned by GM to address stress bending/cracking issues at the bracket holding the endlink. Does anyone know if the GM Part # 22743327 is the original lower control arm & bracket or redesigned version? It's call-out #16 in the diagram included. Obvious I'd want to order the redesigned version to avoid having future issues.

The pic shows the damage to my driver side lower control arm at 23,000 daily driver (no track duty) miles. The endlink was still attached to the bracket, I heard a loud "thump" from the rear of the Camaro when making sharp left turns in the weeks prior to seeing this, though you can see the stress cracks after it was unbolted. I'm using the Pfadt Rear Lower Control Arm Reinforcement Bracket to bolster the OE control arm bracket until I can get the redesigned part - http://www.pfadtracing.com/catalog/p...roducts_id/242

Many thanks to Matt at East Coast Supercharging for his help on this issue.

PfadtRacing · 10-31-2011, 05:33 PM

That's chewed right up, even with a reinforcement bracket I wouldn't expect that to last too much longer. The lower control arms are surprisingly not that expensive and it may be a good idea to get that arm replaced pretty quickly.

The GM control arm redesign was for the 2012 SS FE4 suspension package and ZL1, and completely changes the way the rear sway bar bolts to the control arm. It moves the sway bar attachment point from inboard of the shocks to outboard. While we can't confirm whether or not the part number you posted is also the redesigned arm, the FE4 package control arms also seem to have the correct brackets to bolt the 2010 and 2011 sway bars too. The brackets that your sway bar will bolt too should remain unchanged, so if you're swapping arms swap the reinforcement plates on as well.

Unless you're also looking to swap the sway bars from a 2012 FE4 car, the replacement 2010 or 2011 rear lower control arms with our brackets and endlink update will offer the best solution available for your car.

mhog · 10-31-2011, 05:54 PM

Did you checkout the ones made by BMR. They will have an adjustable one soon . http://www.camaro5.com/forums/showthread.php?t=170832

JusticePete · 11-01-2011, 02:14 AM

How do we come to the conclusion that the OE arm is at fault when there are aftermarket parts attached to it???

How do we come to the conclusion that GM redesigned the lower control arm to reinforce it because of cracking?

If you order a lower control arm from GM you will find it has two sway bar mounting points. The inner mounting point is the same as it has been since the start of 5th Gen production. There is a new outer sway bar mounting point for the new sway bar design. The new arm works as a replacement part for the 10, 11 and 12.

The change in sway bar mounting position was driven by the desire to improve the balance of the car and increase sway bar efficiency with better geometry. It had absolutely nothing to do with the sway bar mounting tab cracking.

As for a repair, we have had excellant success with our weld in support on failimng arms. To my knowledge this is the only solution that has been tested in the field to repair a cracked arm. PQ's 'repaired' arm. When I straightened it out the arm was in far worse shape than the original photos showed.

It has been in service for months and is functioning perfectly. We belive the problem with the RLCA is very limited in scope. With all the focus this thread has created, there are just a few failed RLCA endlink tabs reported. For those looking for a bullet proof solution, the Pedders welded in tab offers the most stability.

Vertically the welded tab holds the bracket in place.
Horizontally the top weld adds stability.
Welding in the corners reduces cracking in the corners caused by the stress of bending the bracket during manufacture.
Doubling the thickness of the tab reduces lateral flexing.
Because the welded in tab maintains the OE arm dimensionally, there is minimal change in load at any given point.

We alson have a bolt in solution.

This solution addresses the structural integrity of the OE endlink tab.

The folded steel slides over the OE tab increasing the thickness from 2.8mm to 8.4mm
The fold at the top increase lateral stability
The wings mirror the design of the OE tab to increase stability and prevent cracking in the corners
The bottom plate assures even distribution of load
The endlink stud and through bolt secure the bracket

tjd24 · 11-01-2011, 07:39 AM

Thanks all for the responses. I've seen the stock sway bar/endlink cause similar damage so this issue is not confined to aftermarket upgraded sways and endlinks.

I've ordered replacement lower control arms and will use the Pfadt reinforcement bracket for extra strength.

Pete - I appreciate your detailed response and your bolt-on offering though at $129.99 for both when the OE lower control arm is $30-$40 each I'd have to take a hard look at the BMR lower control arm at $259 for the pair given it's an overall upgrade from OE.

PfadtRacing · 11-01-2011, 10:28 AM

Quote:

Originally Posted by tjd24

Thanks all for the responses. I've seen the stock sway bar/endlink cause similar damage so this issue is not confined to aftermarket upgraded sways and endlinks.

I've ordered replacement lower control arms and will use the Pfadt reinforcement bracket for extra strength.

Pete - I appreciate your detailed response and your bolt-on offering though at $129.99 for both when the OE lower control arm is $30-$40 each I'd have to take a hard look at the BMR lower control arm at $259 for the pair given it's an overall upgrade from OE.

Tom, I think it is also important to note that the new control arms with the outboard pick up point also includes a beefed up tab for the original attachment point. It is now appx 3.6mm, up from 3.1mm, which translates into 16% thicker. Did you happen to give Gene a call?

JusticePete · 11-02-2011, 02:06 AM

My opinion of the OE arms is different than most. In all our testing, in all our track time, we have yet to see any OE arm damage even though we run a 32mm monster rear bar. If there are 50 reports of damaged rear lower control arm sway bar tabs on the forum it would be a lot. In a single model year GM sells conservatively 80,000 Camaros or puts over 160,000 arms in service. At this time there are more that 320,000 rear lower Camaro control arms in service. The failure rate is statistically insignificant.

We made that very clear in the original thread started by PQ. The weld in tab is a proven fix for partially damaged arms. In a new arm it is absolutely bullet proof. The bolt in bracket we produced is a complex piece to manufacture. It does more than necessary. It also isn't cheap.

You list a range of options and have done your research. I respect your choice.

tjd24 · 11-02-2011, 11:01 AM

Quote:

Originally Posted by PfadtRacing

Tom, I think it is also important to note that the new control arms with the outboard pick up point also includes a beefed up tab for the original attachment point. It is now appx 3.6mm, up from 3.1mm, which translates into 16% thicker. Did you happen to give Gene a call?

Thanks - exchanged emails with Patrick - decided to order with GM Parts Direct.

Quote:

Originally Posted by JusticePete

You list a range of options and have done your research. I respect your choice.

I appreciate all the responses and coaching.

JusticePete · 11-07-2011, 06:16 PM

For what it is worth, I just got back from SEMA and measured the arms we have here. They measure 3.2mm.

11-01-2011, 02:14 AM	#4
JusticePete Drives: Camaro Justice Join Date: Jun 2007 Location: Virginia Posts: 20,174	How do we come to the conclusion that the OE arm is at fault when there are aftermarket parts attached to it??? How do we come to the conclusion that GM redesigned the lower control arm to reinforce it because of cracking? If you order a lower control arm from GM you will find it has two sway bar mounting points. The inner mounting point is the same as it has been since the start of 5th Gen production. There is a new outer sway bar mounting point for the new sway bar design. The new arm works as a replacement part for the 10, 11 and 12. The change in sway bar mounting position was driven by the desire to improve the balance of the car and increase sway bar efficiency with better geometry. It had absolutely nothing to do with the sway bar mounting tab cracking. As for a repair, we have had excellant success with our weld in support on failimng arms. To my knowledge this is the only solution that has been tested in the field to repair a cracked arm. PQ's 'repaired' arm. When I straightened it out the arm was in far worse shape than the original photos showed. It has been in service for months and is functioning perfectly. We belive the problem with the RLCA is very limited in scope. With all the focus this thread has created, there are just a few failed RLCA endlink tabs reported. For those looking for a bullet proof solution, the Pedders welded in tab offers the most stability. Vertically the welded tab holds the bracket in place. Horizontally the top weld adds stability. Welding in the corners reduces cracking in the corners caused by the stress of bending the bracket during manufacture. Doubling the thickness of the tab reduces lateral flexing. Because the welded in tab maintains the OE arm dimensionally, there is minimal change in load at any given point. We alson have a bolt in solution. This solution addresses the structural integrity of the OE endlink tab. The folded steel slides over the OE tab increasing the thickness from 2.8mm to 8.4mm The fold at the top increase lateral stability The wings mirror the design of the OE tab to increase stability and prevent cracking in the corners The bottom plate assures even distribution of load The endlink stud and through bolt secure the bracket

11-01-2011, 07:39 AM	#5
tjd24 Thank you Oshawa/St.Cats! Drives: was 2010 2LT RS 2G1FC1EV4A9103434 Join Date: May 2009 Location: NW NJ Posts: 3,481 View My Garage	Thanks all for the responses. I've seen the stock sway bar/endlink cause similar damage so this issue is not confined to aftermarket upgraded sways and endlinks. I've ordered replacement lower control arms and will use the Pfadt reinforcement bracket for extra strength. Pete - I appreciate your detailed response and your bolt-on offering though at $129.99 for both when the OE lower control arm is $30-$40 each I'd have to take a hard look at the BMR lower control arm at $259 for the pair given it's an overall upgrade from OE. __________________ #3434 Born 4-15-2009, Delivered 5-22-2009 BBOMG 2/3/4 - Traded-in 8/31/2019: Last edited by tjd24; 11-01-2011 at 09:37 AM.

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10-31-2011, 05:13 PM	#1
tjd24 Thank you Oshawa/St.Cats! Drives: was 2010 2LT RS 2G1FC1EV4A9103434 Join Date: May 2009 Location: NW NJ Posts: 3,481 View My Garage	Lower Control Arm - GM Redesign Status? I understand that the lower control arm was redesigned by GM to address stress bending/cracking issues at the bracket holding the endlink. Does anyone know if the GM Part # 22743327 is the original lower control arm & bracket or redesigned version? It's call-out #16 in the diagram included. Obvious I'd want to order the redesigned version to avoid having future issues. The pic shows the damage to my driver side lower control arm at 23,000 daily driver (no track duty) miles. The endlink was still attached to the bracket, I heard a loud "thump" from the rear of the Camaro when making sharp left turns in the weeks prior to seeing this, though you can see the stress cracks after it was unbolted. I'm using the Pfadt Rear Lower Control Arm Reinforcement Bracket to bolster the OE control arm bracket until I can get the redesigned part - http://www.pfadtracing.com/catalog/p...roducts_id/242 Many thanks to Matt at East Coast Supercharging for his help on this issue. Attached Images __________________ #3434 Born 4-15-2009, Delivered 5-22-2009 BBOMG 2/3/4 - Traded-in 8/31/2019:

10-31-2011, 05:33 PM	#2
PfadtRacing Drives: 2010 Camaro, 2006 Z06 Join Date: Feb 2009 Location: SLC, UT Posts: 3,370	That's chewed right up, even with a reinforcement bracket I wouldn't expect that to last too much longer. The lower control arms are surprisingly not that expensive and it may be a good idea to get that arm replaced pretty quickly. The GM control arm redesign was for the 2012 SS FE4 suspension package and ZL1, and completely changes the way the rear sway bar bolts to the control arm. It moves the sway bar attachment point from inboard of the shocks to outboard. While we can't confirm whether or not the part number you posted is also the redesigned arm, the FE4 package control arms also seem to have the correct brackets to bolt the 2010 and 2011 sway bars too. The brackets that your sway bar will bolt too should remain unchanged, so if you're swapping arms swap the reinforcement plates on as well. Unless you're also looking to swap the sway bars from a 2012 FE4 car, the replacement 2010 or 2011 rear lower control arms with our brackets and endlink update will offer the best solution available for your car.

10-31-2011, 05:54 PM	#3
mhog Drives: 2010 V6 Camaro 2LT/RS Join Date: May 2011 Location: NC Posts: 447 View My Garage	Did you checkout the ones made by BMR. They will have an adjustable one soon . http://www.camaro5.com/forums/showthread.php?t=170832

11-02-2011, 02:06 AM	#7
JusticePete Drives: Camaro Justice Join Date: Jun 2007 Location: Virginia Posts: 20,174	My opinion of the OE arms is different than most. In all our testing, in all our track time, we have yet to see any OE arm damage even though we run a 32mm monster rear bar. If there are 50 reports of damaged rear lower control arm sway bar tabs on the forum it would be a lot. In a single model year GM sells conservatively 80,000 Camaros or puts over 160,000 arms in service. At this time there are more that 320,000 rear lower Camaro control arms in service. The failure rate is statistically insignificant. We made that very clear in the original thread started by PQ. The weld in tab is a proven fix for partially damaged arms. In a new arm it is absolutely bullet proof. The bolt in bracket we produced is a complex piece to manufacture. It does more than necessary. It also isn't cheap. You list a range of options and have done your research. I respect your choice.

11-07-2011, 06:16 PM	#9
JusticePete Drives: Camaro Justice Join Date: Jun 2007 Location: Virginia Posts: 20,174	For what it is worth, I just got back from SEMA and measured the arms we have here. They measure 3.2mm.