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

[JusticePete]

Originally Posted by MIQ

I'll be installing my rear springs today and will inspect them. I only have 500 miles on it right now so I don't expect to see anything wrong. Or will I? :(

You will be FINE as long as you make certain your reassembly gets everything tight. If you are reusing the OE endlinks and nuts I suggest you use LocTite and place a hardened washer on the nut side. As alarming as the picture is, it isn't in any way a common failure. In a worst case full failure scenario the OE arm is available for under $50 shipped from numerous sources. Just get the endlink assemblies tight the first time and don't worry.

[PAUL SS]

Just to be clear I was not ragging on PFADT springs, just pointing what I saw to PQ who was asking for feedback. At some point I will most likely have some of their products in my car.

[JusticePete]

Originally Posted by PAUL SS

Just to be clear I was not ragging on PFADT springs, just pointing what I saw to PQ who was asking for feedback. At some point I will most likely have some of their products in my car.

I for one, did not think you were.

[TJ91]

so if I install drop springs only, on my v6, will I run into a similar problem?

[JusticePete]

Originally Posted by TJ91

so if I install drop springs only, on my v6, will I run into a similar problem?

Nope. Just make sure your nuts are tight

[PAUL SS]

Originally Posted by JusticePete

Nope. Just make sure your nuts are tight

OUCH!

[JusticePete]

Originally Posted by PAUL SS

OUCH!

Especially when you hit them with the air gun

[BackinBlackSS/RS]

Originally Posted by PQ

I was under the car the other day and decided to inspect the entire underneath. Well, I found this broken braket peice that is basically the control arm. It is the peice welded onto the control arm that the end links to the sway bar connects to.

You are abusing your car.

[JusticePete]

Originally Posted by BackinBlackSS/RS

You are abusing your car.

Nah, he is driving it like he owns it

In some ways you are correct, but that is exactly why many of us bought a 5th Gen. We planned to abuse it, I mean use it, from day one. One of the things we don't do is check our nuts from one end of the car to the other on a routine basis. The cars are very fast stock with more brake HP than engine HP. With a few mods, they are running race car speeds, but for the most part maintained like a street car. Bottom line, if the nuts were tight this thread doesn't exists.

[PQ]

Originally Posted by Avalnch

The other side is starting to crack too.

lol, I still don't have the answer to wether that's a crack or an OE slit.

Originally Posted by CoyoteRiverRacing

PQ - Did you find better LCA arms?

TIA
Chet

I'm thinking I don't need them.

Originally Posted by BMR guy

This is the third control arm I have seen with this problem. The OE brackets are only 1/8" material and there is insufficient material surroundling the bolt hole. To the OP, where the nuts loose on the end link when you found it this way?

During our control arm testing, we actually updated the sway bar mounts on the control arms specifically because of these failures. The sway bar mounts were increased in thickness to 3/16" material and the hole has a full 1/2" of material around it's radius...

Are you selling them? If so, how much? ]

Originally Posted by JusticePete

The key take aways from this thread is how critical it is to get the endlink nuts tight to GM torque specifications the first time and knowing that the OE nut loses quench every time it is turned. With proper care at the time of installation your endlink nuts should remain tight in place and your lower rear control arms will provide excellent service. There is NO brand issue. Your OE arms are good to go. Get the endlink nuts tight the first time.

Buy a 55 gallon Drum of LocTite and just dip everything

Good stuff Pete. And thanks again for your help. I still got the new end links though.

Originally Posted by BackinBlackSS/RS

You are abusing your car.

Originally Posted by JusticePete

Nah, he is driving it like he owns it

In some ways you are correct, but that is exactly why many of us bought a 5th Gen. We planned to abuse it, I mean use it, from day one. One of the things we don't do is check our nuts from one end of the car to the other on a routine basis. The cars are very fast stock with more brake HP than engine HP. With a few mods, they are running race car speeds, but for the most part maintained like a street car. Bottom line, if the nuts were tight this thread doesn't exists.

Typicaly I look my car over from time to time anyway. Bonnie accused me Sunday of being under my car "Only because Chris is"

[BMR guy]

I agree with Pete, 99% of all street cars will never have this happen unless a nut is left loose and the end link stud oblongs the hole. Every incident I have seen have been on hardcore cars that see a lot of drag strip use and are running larger diameter rear sway bars.

The sway bar end link mount is located approximately in the middle of the control arm. I assume it was designed this way primarily for packaging purposes as placing it further out on the control arm would have provided more controlled anti-roll characteristics from a much smaller sway bar. As it is, more rate is required to overcome the leverage, producing much more load on the sway bar mount.
Keep in mind that the rear sway bar on the upcoming ZL1 is rumored to be much wider which would place these mounts further out on the control arms. Maybe this isn't such an isolated incident after all...

Our dragrace anti-roll bar (will be released soon) is rated at 3614 lbs/in., that's 780% more than the OE bar. After a certain power level, it becomes necesarry to run high rear bar rates for launch consistency. These higher rates place a lot more load on this mount and since it is a single shear mount the 1/8" material just won't cut it. In summary, it is understandable in these conditions that there are failures but in a typical street car, I doubt it will ever be an issue providing the nuts are tight.

[PQ]

Originally Posted by JusticePete

Bottom line, if the nuts were tight this thread doesn't exists.

Ya, but we wouldn't have learned anything here either........

Leave it to me to tear it up so we can learn. Just doing my part. You guys are welcom.




Oh. And Pete, or someone, is this a normal slit by design, or do I need to order another control arm as well?

[GTAHVIT]

For what it's worth. I installed my pedders sways and coilovers on Saturday...

Made extra sure everything was tight.

Went for about a 15 mile ride on Sunday. Drove to work on Monday and rechecked everything in the rear... I was chasing a rattle that turned out to be an exhaust hanger...

All of my sway bar endlinks were lose and a couple other bolts had loosened up a bit...

I'm gonna check the front tonight.. I'm guessing like header bolts... we'll need to recheck them a few times until these fasteners get a chance to seat... especially the DIY guys who don't have shop quality tools.

[GTAHVIT]

I'll look at mine tonight bro, I'll see if there is a slot... I'm guessing based on what the pros are saying, it isn't supposed to be there.... Not if we are concerned about elongating the hole... it wouldn't make sense to put an "expansion" slot in there which would defeat the purpose if I understand the failure correctly.