Has anyone broke one of these yet? (Rear Lower Control Arm Endlink Tab)

[Mr Twisty]

Originally Posted by Rob@WretchedMS

Smokey had a similar philosophy to myself, he didn't think outside the box, he used a bigger box.

One of my favorites was using a fan to drive the alternator so the engine didn't have to, lol (NASCAR didn't like that, lol)

My favorite is the 7/8 scale Chevelle... The world may never know

[Rob@WretchedMS]

lol

[JusticePete]

Originally Posted by PQ

You bet. Just let me know. I'd have to get it realigned, but no big deal.

The alignments are on me.

[2SSRS@Gen5diy]

My favorite was the supercharger he made out of the the torque converter and the auto trans in the race car, Like he said its free power.

[PQ]

Originally Posted by JusticePete

The alignments are on me.

[TAG UR IT]

I just wanted to say that I LOVE this thread....

....especially since mine are failing as well and I'm going to need to get a permanent solution.

But really. VERY educational thread. THANKS!

[PQ]

Originally Posted by TAG UR IT

I just wanted to say that I LOVE this thread....

....especially since mine are failing as well and I'm going to need to get a permanent solution.

But really. VERY educational thread. THANKS!

Me too. I get to be part of some R&D........

[GTAHVIT]

Wow... I have to say... I Reeeeaaaally Like what BMR has come up with... How can you argue with the color RED... ...



Again, assessing each solution here... My uneducated impression is that, to me, it makes sense to put the reinforcement on the inboard side of the tab. But I'm sure that's arguable as the nut and the endlink are both applying pressure to the tab on either side as it articulates due to the added resistance of the bigger sway bar...

again, I just "like" the idea of having the extra material on the inboard side of the tab. Don't know if it's better or not?

BMR, when you get these ready, let me know, I'd like to get a set.

[PfadtRacing]

Originally Posted by GTAHVIT

again, I just "like" the idea of having the extra material on the inboard side of the tab. Don't know if it's better or not?

Chris, when we were working out our solution, the main reason we decided to reinforce the outboard side is because of the forces at work in that arm. The force that is breaking these tabs is a torque that is applied by the tension/compression force on the endlink itself, over the distance of the endlink stud. This is equal to the force times the distance from the centerline of the ball inside the endlink to the face of the control arm bracket. Adding material on the inboard side, increases that distance.

We decided that moving the endlink inboard even farther (and increasing the force on the OEM endlink tab) was not the direction we wanted to pursue since reinforcing the material on the outboard side did not have this consequence. Just food for thought behind our design. Hope that helps!

-Blair

[Mr Twisty]

They're all decent proactive solutions, but I'm with PQ, even a hint of bending and I'm pulling out the welder.

Just like fiberglass, two pieces bolted together are as strong as the 2 separate pieces. Mold the 2 pieces together (equivalent to welding in this case) and the strength is multiplied MUCH higher than the individual parts. Any engineers here want to do the math?

[Rob@WretchedMS]

The BMR solution looks better to me, it's bolt in, thicker,
the drawback as posted is it moves the end link in more and increases the angle of it vs the brackets, a better solution would be a modified BMR bracket that fits on the upper portion on doesn't change the geometry of the link.

The BMR part does look like a more superior fix than the Pfadt plate, and being a bolt on part is good also.

[PQ]

Originally Posted by MisterCamaro69

They're all decent proactive solutions, but I'm with PQ, even a hint of bending and I'm pulling out the welder.

Just like fiberglass, two pieces bolted together are as strong as the 2 separate pieces. Mold the 2 pieces together (equivalent to welding in this case) and the strength is multiplied MUCH higher than the individual parts. Any engineers here want to do the math?

[GTAHVIT]

Originally Posted by PfadtRacing

Chris, when we were working out our solution, the main reason we decided to reinforce the outboard side is because of the forces at work in that arm. The force that is breaking these tabs is a torque that is applied by the tension/compression force on the endlink itself, over the distance of the endlink stud. This is equal to the force times the distance from the centerline of the ball inside the endlink to the face of the control arm bracket. Adding material on the inboard side, increases that distance.

We decided that moving the endlink inboard even farther (and increasing the force on the OEM endlink tab) was not the direction we wanted to pursue since reinforcing the material on the outboard side did not have this consequence. Just food for thought behind our design. Hope that helps!

-Blair

That is extremely helpful. And I can also see that adding material inboard will also change the angle of the endlink as well. But any ball joint binding that may occur could be overcome by an adjustable endlink, I'd think.

I think the main concern, which is likely to be an appearances issue, is the limited attachment of the tabs, or hooks... I think where people like me question your solution as not as "robust" is that it appears, to the untrained eye, that it's more akin to a washer. Which is an unfair comparison. While in contrast, Pedders is possibly over engineered, and BMR is some where in the middle. Again I'm speaking in terms of appearances. Not capability.

I will again say that I trust what you all say... And if you say your solution will work then I don't doubt that.

[JusticePete]

Originally Posted by MisterCamaro69

They're all decent proactive solutions, but I'm with PQ, even a hint of bending and I'm pulling out the welder.

Just like fiberglass, two pieces bolted together are as strong as the 2 separate pieces. Mold the 2 pieces together (equivalent to welding in this case) and the strength is multiplied MUCH higher than the individual parts. Any engineers here want to do the math?

The geometry of the bar, and endlink combined with the strength of the material in the LCA creates a laundry list of variables. It is mission critical that the fix not create any new hot spots in the assembly. Additionally, from what I can tell none of these solutions, including Pedders has been tested in real world use for any length of time. In a perfect world, they all work reasonable well and the consumer has multiple choices for a solution. We'll start our rear world testing with a partially failed arm. If our fix prevents further deterioration of the tab on PQs car, then we'll have a very clear indication that it will be relatively bulletproof installed on a good arm. As I said, we'll know in five or six weeks.

Until then. The sky is not falling. The ZETA II rear LCA is a well engineered piece. The failures we are seeing are limited in scope. If you have a failure, the OE replacement arms are cheap. Not everyone will require a reinforced arm. If you are concerned about your arms right now, put a hardened washer on both sides of the endlink tab. Let the MFGs get some time in the field with the variety of fixes and you will be able to make an informed decision.

Once more. Everyone would like to think they know which solution is best. We do NOT know. We think we know, but only time in the field will prove it. It has taken YEARS for this issue to show on the C5Forums. Pedders is in the fortunate position of having a semi failed arm to field test. That will speed our evaluation of our solution. Once we evaluate the cracks in the arm and see no change in condition I'll be pleased to say we know we have a great fix. Until then, we are just like everyone else. We think we have a fix.