C3 Frame Alignment Pins

[Howell Jaynes]

Can someone provide suggestions as to how I can go about making (buying) some frame alignment pins?

I bought, just for sizing, two 5/8 inch by 4 inch bolts. Execpt for being too short, they looked like what I needed. The shanks of these 5/8 bolts were about 0.005 inches less than 5/8 of an inch and they snuggly fit the frame/birdcage alignment holes. I went out and bought two 5/8 by 14 inch bolts, but the shanks of these bolts were surprisingly slightly more than 5/8 of an inch! . I'm now thinking of trying 5/8 inch of plain bar stock. Before continuing to flounder with this problem, I thought I'd post a message. I personally don't have a machine shop capability, but I can cut steel stock, have a tap and die, and a grinder. A suggestion for something I can make at home is will work the best, but I would be glad to pay for a little machine shop service.

I'm all set to lift the body of my 68 Convertible. I only want to lift it about 6 inches to install new fuel and gas lines. I don't need to go higher since I don't have a rust problem and 6 inches will allow me to get some new paint on top of the otherwise hidden parts of the frame. Lifting the body 6 inches or so doesn't seem like a problem, but I want the body to drop back down on the fraame in it's exact proper location. My frame is on jacks (no wheels), so when I start to drop the body, I won't have the option of scooting the frame around. I want the body to drop back in place exactly. When I lift up with my planned six inches, I will install extra long bolts in the 8 mounting holes and radiator frame to crossmember holes all to help prevent body shift. Also, ....any suggestions?

Thanks very much

[Chuck R.]

Re: C3 Frame Alignment Pins

I'll probably have my head handed to me here but it won't be the last time I'm sure Howell

They could very well have been just 5/8" round stock as you suggest.

As the process had to be fairly quick being on and assembly line, it couldn't have been too too complicated.

I'll wager that they were just a comfortable semi tight fit to get the body set in place so that the body mount bolts could be caught. Nothing extravagent.

Now let's see what the pro's say,

With only 6" clearance, your still going to be challenged a bit working the lines up and over the kickups. But, 6" clearance is certainly alot better than 0 though.

I think I would rest some wood blocks between the frame and the body just in case something gave to protect your hands/fingers.

You probably already had that covered though, it's just the worry wart in me

Good luck with it,

Chuck

[Chuck R.]

Re: Also

I'll bet the alignment pins had tapered ends.

I'll go away now.

Chuck

[John H.]

Re: Also

In production, tapered guide pins were used from the bottom up at the driver's side #1 and #4 mounts to locate the body to the frame at Body Drop.

[Chuck R.]

Re: Learn something new every day Thanks John *NM*

[Chuck S.]

Re: Learn something new every day Thanks John

Howell, my opinion is that you are complicating this process to the point where it could get you into trouble.

In my experience, aligning the body bolt holes is not that difficult; place partial body weight on the frame and use a bar to align the holes as you slowly lower the body. Having all those links between the body and the frame may limit your flexibility if you encounter problems. My opinion is GM only used the alignment pins to speed up the process...taking a little longer is not a problem for you.

I would recommend that you raise the body high enough for your work, then place blocking between the body and the frame (two 4X4s full frame width?), and lower the body back onto the blocking. I would not depend on the lift rigging while working underneath. It's just like using jackstands...only difference is that a hydraulic floor jack is 100X more reliable than most of those lift slings.