Strongest rear sway bar end link? I broke 3 sets...

[Fastbrew]

FYI ---

I felt a little lost choosing a sway bar until I ran across this chart at Perrin
http://perrinperformance.com/i-13324...-fr-s-brz.html

It shows their different size bars and the effect at each position.

SPECIFICATIONS
PERRIN 16mm Bar Hole #1 30% Stiffer than 14mm OEM bar
PERRIN 16mm Bar Hole #2 65% Stiffer than 14mm OEM bar
PERRIN 16mm Bar Hole #3 116% Stiffer than 14mm OEM bar
PERRIN 19mm Bar Hole #1 150% Stiffer than 14mm OEM bar
PERRIN 19mm Bar Hole #2 243% Stiffer than 14mm OEM bar
PERRIN 19mm Bar Hole #3 347% Stiffer than 14mm OEM bar
PERRIN 22mm Bar Hole #1 400% Stiffer than 14mm OEM bar
PERRIN 22mm Bar Hole #2 535% Stiffer than 14mm OEM bar
PERRIN 22mm Bar Hole #3 729% Stiffer than 14mm OEM bar

[swarb]

What about these? 5 year warranty seems good. Not sure if they is any room for twisting.
http://perrinperformance.com/i-13324...-fr-s-brz.html

[FLASCH]

Originally Posted by swarb

What about these? 5 year warranty seems good. Not sure if they is any room for twisting.
http://perrinperformance.com/i-13324...-fr-s-brz.html

Thanks for the suggestion. With the polyurethane end links worry about 2 things: 1) With my car being lowered 1.5", won't I need the end links to be adjustable so I can fit them? They seem to be designed for the stock ride height. 2) Polyurathane being plastic, they are bound to stretch/creep over time. They may not break, but will definitely be much longer after extended use, compromising their effectiveness.(?)

[FLASCH]

Originally Posted by kbye

If it's always one side consistently breaking, the issue might not be the end link but the positioning of the centering rings on the sway bar. Have you checked that the centering distance is the same on both sides?

It's a good point. Edge Motorwerks said they had checked that when they found the second set broke, but I didn't check that last yesterday when I found the third set broke. I'll check it again.

[strat61caster]

Originally Posted by FLASCH

It's a good point. Edge Motorwerks said they had checked that when they found the second set broke, but I didn't check that last yesterday when I found the third set broke. I'll check it again.

Is the sway bar captured with collars? Could it slide laterally when disconnected from the links? Maybe under cornering load it shifts and puts undue stress on the link?

The links look like they are shearing, not stretching or compressing, I'd guess there's some unforeseen force left/right/forward/back.

[redlined600]

IMO this is coming from one of three things. Your bar didn't have locating collars and is moving laterally and binding. Your bushings are binding and not allowing the bar to rotate. Or, most likely, the end links are poorly designed.

End links with a bushings, like the white line design, are not designed to be used with an adjustable swaybar. This is compounded when lowered as the distance between the LCA and swaybar becomes smaller.


Either get the Perrin spherical end endlinks, $$$. Or make your own. Or check out 949 racing's endlinks (for a miata), it would take a little bit of modification (spacers for the arm and a through bolt)but they could work just fine and are cheap.

My .02$ is manufactures completely dropped the ball on endlinks for this car.

[Briankbot]

Originally Posted by redlined600

End links with a bushings, like the white line design, are not designed to be used with an adjustable swaybar. This is compounded when lowered as the distance between the LCA and swaybar becomes smaller.

Incorrect, though spherical would help.

The whiteline rear end links are designed to be used with an adjustable bar. The end link bushing end has three positions to match the three positions on whiteline's adjustable rear bars. The three positions are achieved by placing the gold colored spacers on either side of the link, or both in the front or both in the rear of the link. This locates the link either in the middle, front or rear of the control arm. It is necessary to use a vice or something similar to push the pin pressed into the bushing to match the position of the gold spacers.

So my question to the OP is this: did you make sure the links were set to match the position on the hole you were using in the bar?

From what your picture looks like it seems like the links were not installed correctly. The link appears as though it would have been positioned in line with the hole on the bar you are using if the gold spacers were together on the axle side of the control arm.

[solidONE]

^ was just about to suggest something with spherical bearing on the control arm side. May be the answer to your endlink woes... maybe. Try to find a set using the beefiest threads on the rodends as you can. Otherwise you may be able to put together a set, as someone suggested, by sourcing a set of rod ends to fit the ones you already broke. Th's if you can find the size you need to fit those whitelines.

[redlined600]

Originally Posted by Briankbot

The whiteline rear end links are designed to be used with an adjustable bar. The end link bushing end has three positions to match the three positions on whiteline's adjustable rear bars. The three positions are achieved by placing the gold colored spacers on either side of the link, or both in the front or both in the rear of the link. This locates the link either in the middle, front or rear of the control arm. It is necessary to use a vice or something similar to push the pin pressed into the bushing to match the position of the gold spacers.

I didn't know this, so I'll give white line a little credit. Even still it sure looks like the adjustment range of his bar exceeds the physical edge of the LCA. Endlinks with spherical ends on both sides would be better.

[PERRIN_Chris]

That is really crazy that you've been through so many endlinks. I'd check with Hotchkiss to see if they've ever heard of that before. If it's putting so much stress into the endlink that it's making it break, and bending even the lower bolt, then something weird is going on with the bar I'd think.

[wheelhaus]

Originally Posted by solidONE

^ was just about to suggest something with spherical bearing on the control arm side. May be the answer to your endlink woes... maybe. Try to find a set using the beefiest threads on the rodends as you can. Otherwise you may be able to put together a set, as someone suggested, by sourcing a set of rod ends to fit the ones you already broke. Th's if you can find the size you need to fit those whitelines.

This is my bet. The adjustable positions on the bar are causing the endlink to deflect away from the control arm bushing. Add in an arc-shaped travel path, and at the extremes (even just squat from acceleration) the end link is forced to deflect even farther along an axis that it can't handle much of.

In other words, the bolt appears to get side loaded (because the bushing will only flex so far) and is getting fatigued, and shearing from the constant cyclic load every time the suspension moves.

I also would recommend heavy duty spherical joints. It might be a little more expensive, but will alleviate the side-load (if that is what's causing it). Just make sure that the joint's deflection will more than cover the angles necessary for the entire range of travel or you'll have the same problem all over again.

edit- the only other thing that might cause it is if the suspension components (or just the swaybar) is somehow binding on something.

[Gunman]

Looks like the bar is spaced as Hotchkis suggests for the med-stiff setting. I'm pretty sure their end links use Aurora rodends too. I'll PM you the email for the engineer that designed the Hotchkis bar setup, and maybe he can help sort out the issue.

[solidONE]

Originally Posted by wheelhaus

This is my bet. The adjustable positions on the bar are causing the endlink to deflect away from the control arm bushing. Add in an arc-shaped travel path, and at the extremes (even just squat from acceleration) the end link is forced to deflect even farther along an axis that it can't handle much of.

In other words, the bolt appears to get side loaded (because the bushing will only flex so far) and is getting fatigued, and shearing from the constant cyclic load every time the suspension moves.

I also would recommend heavy duty spherical joints. It might be a little more expensive, but will alleviate the side-load (if that is what's causing it). Just make sure that the joint's deflection will more than cover the angles necessary for the entire range of travel or you'll have the same problem all over again.

edit- the only other thing that might cause it is if the suspension components (or just the swaybar) is somehow binding on something.

Even a completely stock rear suspension will see side load on the bushing. Only thing is that the stock link has enough give in the rubber bushing to not break. Also it's not a threaded connection so they will stretch/bend and deform before it would break. The threads just make it that much easier to shear off the way those whitelines did on his car.

Edit:
Was working under the car last night so I snapped a pic.


Factory control arms, swaybar, endlink. As you can see it is cocked at an angle and not a right angle.