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Substituting Ball Joints for Heim Joints

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Old 10-21-10, 10:27 PM
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Substituting Ball Joints for Heim Joints

I've got a bit of a dilemma. I've got an older roll-center correcting strut housing that was a collaboration between Tony Wolford (AWR) & Yaw Power (don't know if they're even around anymore). It's a great design-truly works to raise the roll center that pretty much gets buried when overly lowering the 2nd gen.



Back to my dilemma. The control arms included with the package are, to me, are the weak point within the design. While light and efficient, they shorten the wheelbase by @ an inch (see above) as well as reduces the amount of available caster-I want to get it back!



what I'm looking to do is utilize the OEM arms. Where the arm situates the ball joint, I'd like to add Heim joints in their place. My questions are;

1. Anyone know FOR SURE what the ball joint arm is made out of? Someone from Raytheon said it looked like Titanium! LOL, I placed a magnet on it and it stuck (and this guys was a material inspector)

2. Would grade 8 bolts be strong enough to handle the compression forces it will see in a 1.3g turn or should I go higher?

I have the ability to turn any spacers needed (I have a lathe).

Why am I doing this? I'd like to have the ability to fine-tune the suspension at specific ride heights. Using Heim Joints with spacers (instead of ball joints) will allow me to do this. Thanks in advance.

~M
Old 10-22-10, 12:42 PM
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Any thoughts? I know I'm not the first one to want to go to heim joints.
Old 10-22-10, 12:55 PM
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I have done this approach on an FD. Replaced the lca outer ball joint with spherical bearing and then used spacers for roll center adjustment. It's pretty simple, but when you use significant spacer it places alot of load on the bolt and you need to keep it very tight. The downside to being that tight is it also introduces alot of stiction in turning.

I'm going to be replacing my setup with some custom lca's that use a racing type ball joint. You can get ball joints from places like Coleman Racing that have removable studs. That way you have the benefits of a ball joint (strength and turning ease) with adjustability.

-Andy M.
Old 10-22-10, 02:06 PM
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Thanks, Andy. I appreciate the info. For your lower control arm, did you use a typical grade 8 bolt to locate the spherical bearing? The good thing about my setup is the outer LCA is sitting a bit lower than the inner, allowing me to use less spacing on my spherical bearings and hopefully reducing loading on the bolts.
Old 10-24-10, 11:57 PM
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Yes, I just used a Grade 8 3/4" bolt. I've seen some people use 5/8" but I wouldn't go smaller than that. If anything loosens up you are going to want the strength. Also, be sure you frequently check it as mine work loose fairly quickly.
Old 10-28-10, 12:45 PM
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You should consider airframe bolts for this sort of thing. Pegasus has them but they aren't cheap.

http://www.pegasusautoracing.com/pro...p?Product=AN12

Can you draw a picture or something of what it will look like when assembled?
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