Balljoint problem

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Turbosbc

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Aug 3, 2018
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Removed front lower control arms, cleaned them and painted. Installed new poly bushings and new tall balljoints. installed them with new moog 5660 springs. (not easy without suitable spring compressor...)

Only to find out that balljoints have wrong taper. Tapers goes too deep and feels like tapers dont match.

Part numbers are ok. these are proforged from rockauto.

I am so pissed.

I read that 78 malibu has one year only spindles but balljoint should be same?
 

pontiacgp

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Mar 31, 2006
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There is only 2 tapers for a ball joint 10 and 7 degrees. What's the taper on the new ball joints compared to the old ball joint
 
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Macguyver

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Mar 21, 2017
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You will need 10 degree taper ball joints. .5" on the lowers and 1" on the uppers. We stock these. There is a catch or 2 though.

Can I use the tall ball joints and use my stock upper A arms?

Yes...and no. They'll physically bolt together and you could drive the car around but there's a catch or two. There's the fact that the original arms on the G Body cars were originally designed to droop down over the frame and have the ball joints at the proper angle for a full range of travel. Once you lower the car, go to taller spindles or ball joints etc. the arms end up closer to level and the ball joints end up close to binding at ride height. Hitting a big bump can bind up the ball joints and put a tremendous amount of stress on them as well as the upper A arms and A arm mounting bolts. They'll only take that for so long before something fails...

Much of it also has to do with alignment. A lot of folks think if their car goes straight and doesn't chew up the tires that it's aligned properly and working as well as it can. They're kidding themselves and they're missing out on a LOT of performance. The alignment specs recommended in the `60s and `70s (and even `80s!) were anything but performance oriented. In fact they've changed little since the 1940s. Today almost every car is using power steering and we're all running high performance radial tires (except for the resto guys but that's another story...) these tires are often more than twice the width of the originals, we've also got another 40 years or so of experience to draw on. What's more, once we've corrected the geometry so that it works like a new performance car it demands the same type of alignment those cars run to achieve peak performance.

Modern performance cars run a LOT more + caster and - camber. The + caster helps the cars track better at highway speeds and gives better steering feel. The - camber helps keep the tire's contact patch flat on the road surface during cornering. It's part of what makes new cars drive like new cars. Using these kinds of settings on older cars yields a BIG improvement in drivability and performance but because they were designed around different specs it's usually impossible to attain the best numbers with stock parts and shims. Lowering the car or increasing the effective spindle height with taller spindles or taller ball joints all add more + camber making it ever harder to dial in a - camber setting (which is what we want). That's the big reason for different upper arms. The taller spindles or tall ball joints make the big geometry improvements and the proper upper A arms make it possible to combine the new parts and geometry with the proper performance alignment, an unbeatable combination!
 

ssn696

Living in the Past
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Jul 19, 2009
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You will need 10 degree taper ball joints. .5" on the lowers and 1" on the uppers. We stock these. There is a catch or 2 though.

Can I use the tall ball joints and use my stock upper A arms?

Yes...and no. They'll physically bolt together and you could drive the car around but there's a catch or two. There's the fact that the original arms on the G Body cars were originally designed to droop down over the frame and have the ball joints at the proper angle for a full range of travel. Once you lower the car, go to taller spindles or ball joints etc. the arms end up closer to level and the ball joints end up close to binding at ride height. Hitting a big bump can bind up the ball joints and put a tremendous amount of stress on them as well as the upper A arms and A arm mounting bolts. They'll only take that for so long before something fails...

Modern performance cars run a LOT more + caster and - camber. ... Lowering the car or increasing the effective spindle height with taller spindles or taller ball joints all add more + camber making it ever harder to dial in a - camber setting (which is what we want). That's the big reason for different upper arms. The taller spindles or tall ball joints make the big geometry improvements and the proper upper A arms make it possible to combine the new parts and geometry with the proper performance alignment, an unbeatable combination!

Not to steal your hard-earned trade secrets, but can you propose a range of alignment specifications for G-bodies that we can provide to our local shop? I know a lot will ride on what combination of stock and aftermarket component we install...
 
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Macguyver

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Mar 21, 2017
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Not to steal your hard-earned trade secrets, but can you propose a range of alignment specifications for G-bodies that we can provide to our local shop? I know a lot will ride on what combination of stock and aftermarket component we install...
In reality the range of alignment does depend on what parts you are using. Static alignment changes when the suspension moves and steering gets involved. So if the suspension is stock, alignment should be stock. If you are using a stage 2 set-up it will be closer to a modern Corvette. If you put more Caster in the car with stock components things get weird pretty fast.
We will do a complete geometry correction front end write-up soon.
 

pontiacgp

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Mar 31, 2006
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I will check the tapers. Is the difference measurable with dial caliber? If the taper is right then my spindles are damaged?

a vernier would be easier to use to compare the ball joint studs I doubt your spindle is the problem if the original ball joint fit properly.
 
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