Tall ball joints?
 

Have purchased a set of Global West front upper control arms. Plan to, for now, use stock lower control arms, but also purchase the global west steering knuckle to help eliminate bump steer.

My question is, would .5” or .9” taller upper ball joints be beneficial with this setup?

I’m working toward more of a resto-mod/pro-touring style car with my 70 GTO. Looking at (hopefully) putting larger (18”) wheels on it later this year. Also looking into lowering the car somewhere around 1” to 1-1/2”.

Thoughts on taller ball joints?

I am running UMI tubular uppers with .5" taller ball joints, stock lowers with new moog rubber bushings and stock height lower ball joint, and 1" lowering springs on my 1971 Cutlass. The car is very responsive and not harsh. No complaints here.

The rear also has UMI parts with both upper and lower using Roto joints, upper being adjustable. I am using UMI front and rear sway bars and a Grand Cherokee steering box. The overall ride is very controlled, my only complaint if I had to do it again would be to go with 17" wheels and a little more sidewall over my 18's.

You can almost always benefit from a .5" tall upper ball joint on the GM short long arm front suspensions. You start getting into issues with the .9" tall ball joint due to ball joint angles and binding. Most often they are added along side a set of lowering springs. The reduction in the bump travel moves the upper arm upward at ride height, increasing the angle on the ball joint. Adding another .9" of effective knuckle height moves that upper arm up further. In a lot of cases, the ball joint on factory designed arms will be near it's bind point just sitting on the ground.

As Scarebird mentioned, you should contact global west and see if they reconfigured the ball joint angles specifically for lowered cars. If that's the case, I'd do a .9" tall ball joint. If not, I'd opt for the .5" tall joint.

On the A-body you may also opt for a .5" tall lower ball joint. This will further help the camber curve. Keep in mind that by adding the lower ball joint you will lower the car half of the effective height gain...or around 1/4".

Edit, the tall lower joint will lower the car by the full amount of the lower joint, so .5".

I spoke with someone at Global West, who stated that, while the control arm can use the tall ball joint, it would provide little to no benefit. The design of the arms supposedly takes care of whatever benefit you may see from the tall ball joint.

Guess I’ll stick with the standard joint instead of a tall ball joint in my Global West CTA-42A control arms.

Hmmm, not sure I'm on board with that assessment.

If I read things correctly, it sounds like he is indeed planning to use GW tubular upper control arms. What I'm curious about is the claim that a 0.5" taller upper ball joint will provide little or no benefit to them.

This is incorrect. no control arm design can alter the camber curve in bump and droop.

Only physically changing the pickup locations for the upper and lower control arms, or changing knuckle height can accomplish that.

What most altered geometry arms do is add in a bit (typically 2 degrees) of static positive caster, or are designed to allow higher levels of caster adjustment.

Caster does create negative camber gain, but requires steering input to achieve it. In auto-x settings where you have a lot of wheel input, the effect is more pronounced. During shallow cornering maneuvers that you see on the street, or perhaps at an open road race during a high speed sweeper, you don't have enough steering input to create enough negative camber gain from the caster to overcome the lousy camber curve in bump travel.

The net result is you don't have enough grip and you start to plow because you've rolled over the sidewall of the tire.

If the global west arm hasn't had the ball joint socket repositioned for lowered cars, go with a .5" tall upper ball joint. It won't completely fix the camber curve, but it does help and with the additional caster you'll be able to get from the upper arms, it's much better than not having it.

Not sure anyone would use a TALLER lower joint But if they did...you are correct.

Each body has a different problem I know F-body's benefit from a 1" tall upper and the A and G bodys have an entire different issue with bump steer.

The A body wants more spindle height than an F body due to where the control arm pickup points are. You can only really achieve that with the use of a tall lower ball joint.

Do it right, do it once. No free lunch.

https://speedtechperformance.com/pro...evelle-a-body/

I don't understand why people still muck with tall joints and crap.


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Leave it alone, save, and do the upgrade when you have the parts/money. Or just leave it stock and live with the level of performance.

If you're going to upgrade, don't screw around. The waste is exponential the more intermediate steps you add.

Don't cheap out. It ALWAYS costs more when you try to cheap out.

If you're daily driver needs a front end rebuild, and/or a trans or something, do you sweat over those costs to a point of pinching pennies?

As for 17+ wheels. Yeah. You WANT 17+ wheels. Vette brakes. Yeah. You WANT big brakes. Why is that not understood? It's not a drawback, it's what you really want anyway. It's the cost of doing biz/upgrades. Accept it. Once you're past all that crap and are able to enjoy the car you love it's all downhill. Just do it.


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There's a bunch of cast wheels, like the US MAG and others, where 18x8s are under $200ea.

18" tires are cheaper, and better than almost all 15, 16, and 17" tires.

Parts are more affordable than ever these days.

Vette rotors, C5/C6 ones, are like $65-$85ea. Calipers are like $120 with the bracket. I just put some on the 442. It's cheaper than doing D52s and wheel bearings.

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C5 powerstop rotors from rock auto: $35ea.

Loaded calipers, with brackets: $45ea.

You can't cry about the cost, period. AND you get big brakes!


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There is no doubt that the AFX spindle is better in every way on these cars. It's lighter, stronger, has a much improved bearing pack, has better camber curve characteristics and much improved bump steer.

That said, the control arms don't know what's attached to them. Effective knuckle height is effective knuckle height and tall ball joints have been used a cost effective way to achieve that (along with the guldstrand mod on F-bodies) for decades without issue.

The same ball-joint binding issues that come into play with OEM, or OEM copy control arms are apparent also with the AFX spindle. It's a function of the upper control arm position, relative to ride height. As a result, the draw backs from using tall ball-joints really comes down to drawbacks of the factory short knuckle more than anything.

For a mildly updated street car, IMHO there's really nothing with doing tall ball-joints. These are wear items and when they're do for replacement, a good tall ball-joint is in the ball-park neighborhood for pricing. There's no drawback anywhere in these systems for adding some spindle height and caster. Do it where it's available.

If you're building a car and your aim is handling performance, I agree that going straight to the AFX spindle is in your best interest. I wish I had, but I was on a pretty tight budget and needed that extra budget elsewhere on the car.

The AFX spindle is a full blown ground up design, and addresses all the inherent issues of any previous designs.

"ATS Tall Spindles aren’t just another visual makeover of a C4 Corvette spindle, they’re a completely new design meant to maximize geometry and performance handling. Manufactured from light weight and super strong forged 7075 T73 aluminum, the upper ball joint mount is raised 2″ to optimize camber curve, making a much greater improvement than merely adding a slightly taller ball joint to stock spindles. The redesigned steering arm and relocated arm mount position greatly improves Ackerman and brings bump steer numbers down to nearly zero."

There is no bind with the spindle and/or control arms/joints. Period. It is not just some 'tall' joint setup. This I believe is the 3rd gen of the AFX, and has taken it multiple steps beyond. It is not some cobbled together solution.

There is an initial cost burden, but, deal with it. Once you get past that, there's no looking back. And even if you missed the boat at one point, you are still way better off taking the bite with some minor loss.

To give you an idea how cost effect these are, originally, they were about $2500 bare for the pair. You still needed control arms, steering arms, etc. Now, most have tubular arms, so in general the cost is less than half of what it originally was, and is better.

I was in contact with Tyler at ATS during the development of the originals, Doug at GW was also involved. Tyler's focus was on 1st gen F cars, and I was the driving force behind bringing these to market for 64-72 a bodies. Search it here and on pro-touring.

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