Dog Tracking

[Ishmael]

Got my 68 Firebird on the alignment rack and the thrust angle is like 38. Way out of wack. The body seems straight but one rear tire is about an inch further forward or closer to the quarter than the other. The springs are fine and the pin is located. The alignment holes on the front subframe were good until the shop tried to line things up. The shock plates were even when I measured from the shock plates to the nearest subframe mounts. But I noticed one plate was 1/2" closer to the rear valance than the other side. I have an 8.5" out of a 73 Ventura in it. Like I said I did measure it and the body and frame seem straight. I was thinking of welding and redrilling the shock plate or using a thrust alignment kit unless there is something else I should be thinking about.
Any ideas?
thanks

[dirty rick]

I would take it to a frame shop and have it measured. If is visibly off you need to correct it not screw with another area to make it look right.

[raustinss]

yeah what that dirty dirty rick said ....there is clearly something WAY out of whack . once you know what then you can start figuring out how to fix it

[TheJDMan]

Is this a multi-leaf rear spring? If so you need to take the axle plates off and make sure the center bolt is not sheared off inside the spring pack. You can't always tell by looking at it from the outside. I have had center bolts shear and everything looks good until you take the tension off the axle clamp bolts and then everything falls apart. I have also sheared the pin on single leaf springs.

[Ishmael]

I am taking it to a body shop to be put on a frame machine. I measured everything according to Pozzi's website and it seemed really close.
The pins are fine. I've had the plates on an off too many times now.
I'm wondering if it has to do with the 8.5" out of the 2nd gen. I've read they are never centered but off to one side by 3/8ths. My rear seems to be the same. Can an axle not being centred throw off an alignment machine?

[dhutton]

How does it drive?

Don

[Ishmael]

It drives fine. It may not be dog tracking. I haven't followed myself. The more I think about it the more I think having a rear that isn't centered is going to throw off the machine. Any ideas on that?

[Rod]

did you put new quarters on?

[ford396]

Yes: a rear axle not centered left to right can throw off an alignment machine. Same as running different offset wheels left versus right ( ask me how I know) :) This depends on the machine and how it is establishing wheelbase.

Bob

[ford396]

Do your own alignment with a couple of plum bobs and a tape measure. Set the car at ride height and drop a plumb bob over the rear axle at each end and check this to your lower ball joints. Should be square if things are not jacked up in the front. There are also reference holes in frame that you could square rear axle to.

[Ishmael]

Yes there were new quarters put on. I hope he didn't mess up. I'll measure again to the alignment holes. I would bet money that centering screwed up the machine. Wow. That was money down the drain.

[David Pozzi]

Drive it down a street as straight as you can. Stop & take a good look at it from behind. See if it's dog tracking.

[hotrodalex]

Or you can get someone else to drive it while you follow in a different car and watch.

[Ishmael]

Wife will follow.