Curious to know if a 70 A-body while being assembled had standard shim placement (and what was it?) in upper control arms while going down the assembly line? I find it hard to believe these cars were put through an alignment process after being assembled since all should be the same? but maybe?
Im putting a chassis back together and just want it close for now.

 

I believe they did have a standard amount, it might be in the assembly manual. I definitely remember reading that in a manual, but I have a lot of different GM cars. I want to say 4 thin...1/16"? Maybe somebody else knows for sure.

 

I am certain they had an alignment machine. You can do that before you put the engine in and body on, you just pick up the sprung chassis with a hoist and drop it on the machine, and it will clamp it down and do it for you.

 

If that were true, most of the cars off the line would have incorrect front end alignment. Do you really believe that?

 

Well Joe, I could be mistaken. I'm like 66 years old and forgotten more than I can remember. But...I've got a LOT of GM assembly manuals here, and at one time looked at every page in all of them. I had thought I saw a specified amount, like 2 per side for assembly. I don't see how that would make every car out of line, if that's the tolerance the tie rod assemblies were set to meet. Like there was a recommended amount for core supports too, from what I recall. I don't believe what Koda says about clamping the chassis down bare. That makes no sense to me because each car weighed a different amount based on model and option load. Of course, it could have been based clamped down on ride height. 1970 was a lot different than 2019, there were no computers to hold all the info. I believe they could do that now, probably roboticaly, but not in 1970. I do believe they aligned them when they left, so there had to be a machine on the line somewhere. Whether it was near the chassis or the end I'm not sure. What makes sense to me is everything is new, so they should be within a certain tolerance. I'm pretty sure the tie rods were like pre-assembled to a certain length. I'm kind of surprised that nobody here actually knows, nobody here has ever seen specified amounts of shims for assembly? I know there's guys here who study the manuals like the Bible.