A year ago I bought a 67 Chevelle SS that already had a QA1 Street Performance upper control arms and sway bar installed. The lower arms, springs and shocks are still basically stock. It also had the stock power steering box, which was really sloppy. I recently installed a new Borgeson 12.7:1 box. The steering was then nice and tight...huge improvement. No more constant steering input on the freeway. The car did want to slowly track to the right, so I brought it in for alignment. Now I'm wondering what the heck is going on with these caster numbers. NEGATIVE 3.15, are you kiddin' me?

The shop is competent and their equipment is top notch. They have done other vintage cars for me in the past with good results. They just couldn't dial in any more positive caster. I got on the phone with QA1 support and we went over the possible issues. The arms are on the correct side, the cross shafts are installed correctly, ball joints appear correctly aligned. The only thing we haven't done is adjust the upper ball joint mount (the QA1's are adjustable). I'll try that, but I don't think there is 8 degrees of positive adjustment there.

Any advice or knowledge would be appreciated at this point. The car drives fine really. Maybe it steers a little too easy, but it doesn't wander and tracks straight. No bump steer either.

Frank

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I just went through something similar but a little different. Installed new tubular upper and lower control arms and ASSUMED they were properly matched.Turned out the lower control arms were 1" too short, but I assumed they were correct so kept trying to push the camber out. Scratched my head a bit before I figured it out.
With yours, it seems the upper control arm center isn't jiving with the lower? That's obviously a ton of caster, seems the parts aren't right.

Are you sure that those new upper arms are compatible with stock lower arms? Some aftermarket arms move the ball joint locations around to improve overall geometry. Point being, those aftermarket upper arms may only be intended to be used with matching aftermarket lower arms.

Also, I think those aftermarket arms have offset cross shafts so if those cross shafts are installed wrong or 180 degrees out they would jack with the caster in a bad way I'd think.

I bring no good advice or knowledge, other than to ask a question.....does the steering return to center? My alignment shop is not top notch (i didnt know this before hand), when they first did my alignment, they set it back to factory specs, and it really didnt return much. When i went back with numbers i got from people here, return to center improved, and is almost 100%, but they could only get +2 degrees with factory control arms.

Pos 2* is a very good setting for stock control arms. Be happy.

Frank, can you post pictures of your shim pack on both passenger and drivers sides upper control arms?

According to tech at QA1, these arms are compatible with stock lowers. I thought the same thing right away, that the PO might have mounted the control arms on the wrong sides. According to QA1tech, the "QA1" sticker is on the forward side of the control arms (not a definitive identifier obviously, but mine are towards the front) and the "bent" side of the control arms should also be towards the front of the car, with the straighter arm towards the rear. Mine appears to be correct, but tomorrow I'll jack it up, pull the tires and check for sure.

Here you go.


Driver's Side Front: 10mm (total)
Driver's Side Rear: 5mm


Pass Side Front: no shims
Pass Side Rear: 5mm

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Can you post a picture of the balljoint end of the arms?

Not seeing why they didn't give you some positive castor, you have plenty of adjustment on those shim packs. They have more on the front than the rear (driver's side), never seen that before. When you say they couldn't give you more pos. castor, did they give a reason?

When I installed my UMI uppers, I made the mistake of getting them on the wrong sides. This was even after reading instructions and thinking I had them on correct. With them on the wrong side, I was getting over 10* of positive caster, so I don't think that's your issue.

jim

I agree. I think you need to find a better alignment shop.

Thanks Jim, feel better knowing I was not the only one to put them on backwards.

Here’s some photos of the driver’s side upper control arm. Some of the guys over on the pro-touring forum say they’re mounted on the wrong side, but QA1 tech doesn’t think so. Any opinion? I’ll get the left/right arm measurements from QA1 today and verify.




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I think they are on the wrong sides also. Don't those arms have some pos. caster built in?