texasTA

I have 17 X 9.5 ZR1s wrapped in 275-40-ZR17 Sumitomo tires. Ever since I have installed these wheels and changed to Hal 12 way adjustable shocks and Hal drag springs my tires have been slightly slanting inward even after two alignments.

Here is my superb graphic illustration:

How tires was before upgrades = [] []
How tires sit now after upgrades = // \\

Obviously, it isn't that angled inside, but it definately goes inward up top.

What could be causing this?
I had an alignment done which helped the problem for about a day or two and then the tire would start to slant.
Took car back in and had the same results. Guy there at Goodyear said that he had the caster (might of been camber he said) as far as it will go. He was refering to some nut that you move to adjust it.

Xride

why do you have drag shocks and springs with those wheels and tires?

Ok first off, the wheels and tires wont do that, cause they are th same size as the stock wheels only wider.

its got something to do with the shocks/springs.


The wheels go in like that at the top (camber) when the car is too low for the adjustment to fix.

it getting better after an alingment is good, it going back after a while is bad, and the only thing that I can think would do this, is something not installed correctly, or not tighten down right.

texasTA

well, I went with the Hals, because they seemed like the best overall shock I could go with. When I am not drag racing, I can set them up for regular driving.

I installed the shocks and springs and am sure that everything went back in just like it came out.

Do you think it could have anything to do with worn out ball joints, tie rods or bushings in the front lower control arm?

I am really at a loss here.

Xride

if it was right after your install, then I would have to say it has something to do with your install.....

How many miles are on your car?
both mine have been very low milage so I have now idea how ot tell worn ball joints, but I would assume some noise would be evident.

texasTA

Well, you see that is why I am not sure the cause. I had a 1997 30th SS that had 9000 miles on it. We put Hotchkis 1" springs and bilstein HDs on that car. It never had this problem. That was with the factory 17 X 9 ZR1s with 275-40-17 tires.

My Trans Am now has 106000 miles on it. I am guessing that the front suspension pieces (ball joints, tie rods or bushings) probably need to be worked over.

Injuneer

How did you set up the lower seats on the HAL's with regard to ride height? The camber change you are describing is typical of a substantial drop in ride height.

And, it may not be all the bad. The stock camber setting is +1-degree. It will generally handle better with camber in the range of -1/2 to -1-degree. In any case, the alignment should be checked.

Is it possible you didn't tighten the lock nut on the lower spring seat adjuster?

texasTA

Injuneer,
when you say "lower seats" are you refering to the bottom "ring" that you have to back off the top "ring" to adjust height? I am almost at the top of the shaft on these shocks. When we installed them the shop I bought the shocks at told me to have the spring perch about in the middle of the shock shaft. When we lowered the car, the wheel wells sat on top of the tires.

So we moved the spring perch up the shaft. To get optimal ride height (lowered, but not to low), the spring perches are way up the shaft. But I am pretty sure we definately tightened down the bottom "ring".

You also said something about tightening the lock nut on the lower spring seat adjuster. Now I didn't have any nuts in my bag of parts. Basically, my Hal drag springs sit on a spring perch, then directly below that spring perch is another perch which tightens up against the top perch to maintain ride height.

Maybe this will help. And so having the tires a little slanted in at the tops is good
I was afraid this would tear up the tires faster.
Thanks for your response injuneer

Injuneer

What you are calling "another perch" is what I am calling the "lock nut". The top piece (your "spring perch") is the spring seat, the bottom piece is the big nut that you tighten to hold the spring seat from rotating.

You need to get the alignment checked. Excessive camber will "tear up the tires"... I was just pointing out that the factory settings aren't necessarily the best.

Badly worn upper and lower A-arm bushings could cause alighment problems. The ball joints would have to be practically ready to fall apart to create the amount of camber change you seem to be describing.

texasTA

I believe that the ball joints are pretty bad. This car was a driver for the lady before. 86000 miles and I doubt she took care of those little things. Anyways, I am going to replace the tie rods (inner and outer), ball joints (upper and lower) and go with a set of BMR tubular lower A-Arms. If this doesnt fix it, then I give up.

Also, the idiots at Goodyear gave me hell about my Panhard Rod (adjustable). I obviously have to use this as I am running 17 X 11 ZR1s with 315-35-17 tires in the rear. I had to move the rear over about 1/4 to 3/8 of an inch over ot the left to properly align the rear end. Those idiots moved the rear back over (this was on the second alignment) and told me that due to that "torsion bar" being installed, it is creating my thrust angle to be off by .25 inches. THey were trying to convince me that my frame is bent and that is what is causing the alignment to not hold, not enough camber, and why the rear end would need to be moved left a 1/4 of a inch.
So should I worry about the frame or just not worry about the thrust angle being off by a 1/4 inch.

THanks

Injuneer

Do you have adjustable LCA's? They would throw the thrust angle off if they were not adjusted to identical length on both sides.

I would follow the shops advice on thrust angle. Something appears to be causing some misalignment in the back... but that would be a separate problem from the excessive camber in the front - normally the shops won't even check thrust angle on a solid rear axle vehicle.

I've been tempted to get the thrust angle checked on my car, since I have moved the axle back with adjustable control arms to make clearance for 28" slicks, and I have moved the body slightly with an adjustable panhard rod to accomodate the 315/35 street tires.

texasTA

No at the time, I was on stock LCAs. I have since gone to boxed BMR LCAs.
So, it probably is a good idea to have a frame shop check out the issue with the thrust angle being out of whack? I wonder if that is a problem for everyone who uses a APHR with 17 X 11s.

LPEdave

I wouldn't extend it that far. I've had the thrust angle measured on my car, with adjustable LCA's, drop brackets, and a Panhard rod adjusted to clear 17x11 wheels, and it was very close to dead on (don't have the sheet with me, but my guess is that means a thrust angle of zero).

Personally I'd be looking for a different alignment shop as well. They don't sound like they're really understanding the whole car here.

Dave

texasTA

Yeah, they completly accused me of putting the "torsion bar" on after the intial alignment. I assured them that when the 17 X 11s went on, the APHR was there also.

I think I am going to go to a different alignment shop to see what they say. I will post up my last alignment specs so you guys can hopefully dissect them.
THanks