[dcygan1]

I'm doing a frame-off / rotisserie restoration of my 65 GTO hardtop. My issue is that I have negative 3 degrees of camber on the right side and negative 0.5 degrees on the left side. The drivetrain is installed, but not the front sheet metal nor interior. Even if they were installed, there's a 2.5 degree difference in the camber from one side to the other.

All of the suspension components are new, including springs, bushings, ball joints, and everything else. The cross measurements of the chassis show that it's square. The distance from the left control arm shaft mating surface to the other is 30-7/8", whereas I believe it's supposed to be 31" making it 1/8" off. Also, there are no alignment shims installed.

I would greatly appreciate any help with figuring out why the camber is off.

[Lemans64]

Kinda sounds as though the frame has sagged, rolled in at top. Adding shim is gonna make it worse so something has to be off.
They do make offset upper control arm shafts to compensate for some sag, but don't think they will look after that. Did frame looked to have taken a Hit?
Are the upper control arms off the upper frame rubber bumpers? Maybe springs too long? Mine was on upper bumpers even with engine in,
like you I had sheet metal off, took springs back out and cut a coil off.

[dcygan1]

The upper arms are sitting on the rubber bumpers. I compared the new springs with the length and number of coils of the originals and they appeared to match. The 1/8" narrower measurement indicates that something is up, but 1/8" isn't a lot. There's also 5/8" between the bottom of the oil and and the top of the center link. If there was a sag, shouldn't it affect both sides the same so the camber angle would be the same left and right, at least that's what I would think. There's no indication of any accident damage.

[JLMounce]

I don't believe you can make an accurate measurement currently as the car is missing too much weight on the front end. Other things to think about, is the car sitting on a level surface? Are the control arm bushings torqued already?

This does kind of seem like a cradle sag issue. You may want to pre-emptively get a set of offset cross shafts.

I would put the front end on the car along with a battery and simulated weight of the core support with filled radiator and heater core, then re-measure. It may tighten up on your as the car sits closer to ride height, which does effect camber. The factory suspension goes positive in compression, so as weight is added, your numbers will move. Also keep in mind that you're never going to have matching shim stacks on these cars. You're almost always going to have one side that has a shim or two extra. What you don't want is one side that has 6 and the other side has 1.

[65 Lamnas]

I'm assuming you're using the stock OEM control arms. You still have several hundred pounds of weight to add to the car with the sheet metal, bumper and interior to install still. I'll also assume the spring are indexed correctly in the spring pockets.

I think it's wise to be concerned at this point, but not time to make a decision until you get the suspension fully loaded with the remaining components of the car. If you still have an issue fully loaded, you can convert the upper shafts to the Moog offset shafts, which will allow additional positive camber. You might have a wee bit of frame sag (not uncommon) going on, and that's what the Moog shafts are designed to fix.

[dcygan1]

The control arms are stock, the springs are indexed to the notches in the control arms, and I have a set of off-set shafts, but they only provide 1-1/4 degree of change. My major concern is that one side is way off while the other is pretty close and should be fine once everything is installed.

[VCho455]

A couple things to try. First verify the floor is completely level and flat (Within 1/8") then using the factory frame alignment measurements (There are here on the site just do a search.) That should determine if the frame has a problem.

If your floor isn't flat and level then use blocks under the wheels to level the car and use a Lazer level to measure from. Just remember to subtract the distance that the Lazer is off the floor from the factory measurements.

Another idea is to remove the all springs and hold the car at ride height then check your camber again. A small hydraulic bottle jack on each corner of the frame is a pretty convenient way to do this test. Once again if your floor is less than perfect a Lazer will help you get the frame level.

[Lemans64]

Could also hang another 400-500 lbs off the front to see if that changes your reading.

[Cardo]

JL Mounce is on the money. Judging by your pictures you are waaayyyyy to early to even be thinking about trying to set alignment. No glass, interior, front end etc. Just the fact that the upper arms are sitting on the bumpers is a deal breaker. None of those upper or lower control arm bolts should be torqued until you have the full weight sitting on the car. That was actually one of the very last things i did when I built my car.

[dcygan1]

Originally Posted by JLMounce

I don't believe you can make an accurate measurement currently as the car is missing too much weight on the front end. Other things to think about, is the car sitting on a level surface? Are the control arm bushings torqued already?

This does kind of seem like a cradle sag issue. You may want to pre-emptively get a set of offset cross shafts.

I would put the front end on the car along with a battery and simulated weight of the core support with filled radiator and heater core, then re-measure. It may tighten up on your as the car sits closer to ride height, which does effect camber. The factory suspension goes positive in compression, so as weight is added, your numbers will move. Also keep in mind that you're never going to have matching shim stacks on these cars. You're almost always going to have one side that has a shim or two extra. What you don't want is one side that has 6 and the other side has 1.

Hi, JLMounce, To answer your questions:

1) The more weight I add to the car, to see how it affects the camber, the more negative it gets thus making the problem worse. If the camber were getting more positive with the added weight, then I'd feel better and stop worrying. Let me know if this is wrong and it should be going in a positive direction, but so far after adding 200 pounds, it went more negative.

2) The car is in my shop on a level concrete floor. I had it on roll around car dollies, but removed those yesterday. I I also made sure the car was level using a self-leveling laser level. All tires have the same tire pressure and appear to have very little tread wear. I also double checked to make sure that both front tires are the same size, which they are, as so are the backs.

3) When I assembled the front suspension, I only torqued down the ball joints, but left the control arm bushing bolts lose to allow for free movement until the car is fully assembled and weighted at which point I'll torque them.

4) The measurement between the two control arm shaft mounting towers is 30-7/8", with the drivetrain installed. I believe this is supposed to be 31" so there's a 1/8" discrepancy, most likely from sag. I'll try and figure out if the sag is causing a 1/16" change to each tower or if one tower is more tweaked than the other.

5) I ordered off-set control arm shafts in case I'll need them, but they will only provide 1.25 degrees of positive camber change.

Thanks,
Doug

[JLMounce]

Is the suspension using a tall spindle or tall ball joints?

How much weight are you adding? You're missing probably 600ish pounds from the front right now.

The camber curve of the factory short long arm suspension moves positive in bump. Unless there are some major changes to the control arm mounts, or the height of the spindle, what you are experiencing is certainly odd.

If the floor is known level, I'd start measuring the frame at locations ahead of and behind each set of wheels to see if the car is sitting anywhere near level or not.

[dcygan1]

Originally Posted by JLMounce

Is the suspension using a tall spindle or tall ball joints?

How much weight are you adding? You're missing probably 600ish pounds from the front right now.

The camber curve of the factory short long arm suspension moves positive in bump. Unless there are some major changes to the control arm mounts, or the height of the spindle, what you are experiencing is certainly odd.

If the floor is known level, I'd start measuring the frame at locations ahead of and behind each set of wheels to see if the car is sitting anywhere near level or not.

I've been thinking about the effects of the suspension geometry contrary to what it actually does. It was my impression that the top of the tires moved inboard as weight is added. I just called Scott Tiemann and he clarified that the top of the wheels move outwards, not inwards, as I had thought. The reason I was thinking this is because the 200 pounds changed the camber in more of a negative direction, not positive. I'm not sure why that happened.

Thank you for helping me resolve this! I can now move forwards and hope that all will be good once the car is fully assembled.

[JLMounce]

Yes if this was a modern vehicle, or you had a lot of extra spindle height, you would likely see that. Sounds like you're set right now and you just need to get the weight on the car, then an actual alignment. Knowing you might have a tiny bit of sag in the cradle, those offset shafts will help.