Well, I am doing the 12" disc swap on my 70, and the ball joints are at the machine shop as I type here. My question: the ball joints are supposed to be turned down .080", right? Does this mean that the diameter must be reduced .080" or does the actual cut have to be .080' deep -- i.e. a .16 reduction in diameter? Please help me clarify this, as I don't want the shop making the choice! Thanks--

I would think diameter, as most machine work is done that way, like on a crank (.010 under decreases the diameter by .010). You could verify it by measuring the spindle hole and unturned balljoint.

When in doubt remove the least amount of material. Cause I can allways take more off but it gets real expensive to put it back on.
Is this comming off the taper that fits the spindle or off the flange that presses into the control arm?
Harley

70,
Do not know the correct answer to your question without seeing the instructions, but in my opinion, I would make sure this is the correct procedure. I personally would not even dream of modifying any suspension component as important as a ball joint. There has got to be another way.

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Bill Koustenis
Advanced Automotive Machine
Waldorf Md

1971 Heavy Chevy - original owner
Team Chevelle #100

Bill and Harley, this is the procedure which has been done for years, at least as long as this conversion has been popular. Sorry I was unclear as to where the material was coming off -- it's being turned down on the housing collar where it press-fits into the relief in the lower A-arm. The steel's not all that hard so it's pretty simple machine work. And since only .080" is coming off, I'm not too concerned with it compromising its structural integrity. Or at least I can hope. http://www.chevelles.com/forum/smile.gif The fact that this conversion has been performed fairly widely is a reassuring thing for me. I'll go get a caliper on the a-arm tonight and measure the hole, and take that measurement to the shop tomorrow morning. Should I leave a little extra so it's still an interference fit? Is, like, .005" enough to snug it in? Thanks much..

You got it, .005 on the plus side should be ok , just check the i.d. of the hole first. Or better yet take the arm to the machinist so he can check it with his equiptment.
Harley

[This message has been edited by Harley (edited 08-04-99).]

70L34, you might want to make sure that your machinist holds a smooth finish on the turned surface also. This is very important for an interferance (press) fit. Good Luck..

It might be good to measure the diameter of the original type of ball joint (the one that fits your control arm)and use that as a target, rather than to just have .080 removed from the larger one. If the two numbers agree, this would give a higher degree of confidence.

Well, I brought the A-arm over to the shop this morning and it turns out that a .040" cut is necessary to get a press fit (.080" diameter reduction). The ball joints fit nice and snugly in the arms now. Anyone planning to convert to camaro spindles ought to make a note of this so they don't make the mistake that I almost did! Thanks--