The Stovebolt Site Forums The Shop Area Paint and Body Shop Hood hinge help PLEASE

I am putting the front clip back together to verify fit before paint. The truck is a 47 GMC 1/2 ton panel. I had 2 sets of hinges but could only find one set. Of course it was garbage and got tossed while a dreaded repop set was ordered. When installing new hinges with the original shoulder bolts, there is too much play in the hood to hinge connection. I no longer have the original hinges to check dimensions but I am hoping someone here might. Also, any timely input on this issue will be greatly appreciated as I want to keep moving forward.

The hood hinge set came with new support springs as well. I got the hood near perfect without the springs. When the springs are installed the hood goes wonky. Looking closely I see movement of the hood at the hinge shoulder bolt connection. I took a micrometer and did some checking. Here are the results;

shoulder on original mounting bolts .368
hole in new springs .374
hole in original springs which I still have .375 - .3785 (not round, no surprise as it is worn)
hole in new hinges for the 4 different hood mounting points .440, .445, .445, .465
Play in new hinge main pivot points .010

When I place an original shoulder bolt in a spring mount hole it feels real good with .006 clearance. When I place that bolt into a hinge hole with minimum .072 clearance, everything goes to heck. I am wondering several things;

1) anybody have any idea what the dimensions are for the shoulder on the new replacement bolts is?
2) does anybody have the measurements of the hole size on an original set of hinges?
3) does anybody have an idea or opinion on how much clearance there should be at the hinge to hood mount location?

As a last resort I am thinking of having bushings installed and new shoulder bolts made to tighten up this mess. I look forward to your ideas.

Did you go through the hood alignment procedure in the manual or as posted HERE?
I'm assuming you did. I can't help on your dimension requests, unfortunately. Maybe someone will chime in to help.

Kevin, I did the hood alignment as per the document you referenced. The issue showed up as soon as the support springs were attached.

I went through a couple rounds of the alignment procedure and was able to compensate for hinge looseness by changing the adjustment without the springs. It takes some head-scratching to figure out which way to shift the hinge mounting bolts - it's not clearly obvious.

Is .072 clearance normal? Add that to all 4 mounting bolts and this thing is moving in every direction, all at the same time it seems! This can't be right.

I recall winding up keeping one inside hinge bolt tight and loosening the other to tap the hinge in the direction I thought it should go.

.072 clearance really sounds like a LOT. I have no idea what the clearance on mine were, but I used original hinges and shoulder bolts (at least the ones that came on the truck when I bought it.)

There was a change made to the hinges at some point. The hinges in my '47 have all 3/8" holes. The shoulder bolt kit that i ordered from one of the vendors came with 2) 3/8" and 4) 7/16". You want to get a shoulder bolt kit for your new hinges.

Thank you Walter. That was a fact I was not aware of. I knew the 47 hinges were different from the 48 and newer in that they had an extra spring connecting the middle of each hinge arm. Good to know about the shoulder diameter. I wonder what year that changed? 7/16 is .4375 so that all adds up.

The new bolts have arrived. The fit is also perfect. Thank you @walterhvogel for the info. I had tossed my old hinges so I did not see the difference. I am wondering what year this change was made to the larger shoulder? Maybe it is just the repop hinges that have the larger size?

I'm glad you are able to keep the momentum on your project. The hinges in my '47 do not have the holes for the extra springs like the '47 hinges are said to have. Assuming my hinges were replaced early on, I could guess they might be from '48. With that the hole change could be '49?