The Stovebolt Site Forums The Shop Area Paint and Body Shop 1946 GMC front clip Assembly Advice Needed

Hi. Mocking up the front fenders and grill on a 1/2 ton 46 GMC. I need some advice on the sequence, and how to manage this alone . I have the inner fenders attached to the cab and radiator support.

These fenders are still rough - I believe I should work the kinks out now, weld the stress cracks, and do as much hammer and dolly work to get them in a straight condition before I fit them? Seems like that the best approach.

Is it best to assemble each fender' one each to the cab and inner fender? and then fit the upper panels and grill? or assemble the front fenders as one unit with the grill holding both halves together and try to slide both fenders and grill in place?

And somehow support it until i can get some bolts into place.

How did you to tackle this task?

Last - Installed the V brace from radiator support to the cab firewall. As you can see - the threaded end lies inside the cab firewall and there is no "stop bolt" on the outside of the firewall. Is this correct? It would seem to me that there is no 'support' with the V brace not locked into the firwall to prevent front to back motion and stiffness to the radiator. I can understand that the radiator assembly could use some free play while driving allowing it to flex. Yet - the side curtains (inner fenders) bolt to the radiator surround effectively reducing that movement anyhow. What are the thought about this? I'm thinking that I can tack a washer to the V bar once everything has been fit together - and then tighten the nut inside the cab to that washer. If - it is the right thing to do. Interesting assembly and engineering. THoughts? I could try to run a die on the threaded rod to increase the length of the threads on the rod- but the bend to fit into the firewall prevents this.

And finally - need a check - is the radiator and support oriented correctly?

Thanks. Tom

Tom,

Each side of the firewall end of the v-brace should have 2 nuts, 2 washers, and one lock washer. One nut on each side of the body sheet metal. There is enough thread length for adjustment of the radiator support. It looks like the nut on yours is drawn in the entire length of the threads at present. I would suggest that you bolt everything together with bolts just finger tight and everything will sort out.

You are in the sweet spot of a restoration...have fun!

Paul

Why didn't you paint the V brace?

Thanks for the responses. Otto - I’m just mocking things up and fitting parts to the cab forward at this point. At some point you bet, that V brace will be so nice that everyone will ignore the rest of the truck and just talk about the V brace!

Paul - this is the perplexing part about this fitment. I have three v braces - all identical from three different sources. The unknown for me is -

Are the GMC braces ‘shorter’ than the Chevy truck braces? Thus allowing for the threads to come through both sides of the firewall?

The side curtains are setting the distance of the radiator support to from the cab. As a result, there is no room to adjust the radiator support forward or back once the curtains are loosely or tightly bolted to the cab.

The V braces - all naturally position themselves (due to the length of the curtains) with the threads inside the cab for each V brace. Those nuts are not tight to the firewall interior … just barely touching if at all.

I am wondering if…I have either Chevy truck V braces and or Chevy truck side curtains on this GMC. Knowing that GMC engines are 1.5” longer than the Chevy engines….(I don’t know why GM would have two different side curtains for each brand though…from a cost and fabrication perspective… that would not make any sense)

I’m not worried about this … just want to assemble correctly. What with the curtains holding up the radiator support in addition to the radiator hoses…. and crossmember support bolts; the radiator should be fine and flex on the frame somewhat.

I agree though –– I’ll assemble the front clip, hood, front fenders, etc in loose fashion – and see what if any adjustment can be made then.

I am attending the NE Chevy and GMC truck show tomorrow - and will see if I can photograph an assembled GMC … maybe get a measurement if an owner would allow.

Last… after all of this this writing: in typical fashion - I am going about this blindly and the hard way … the truck came unassembled and missing many items… so, I am acquiring parts and pieces as I go - hoping for correct fit and searching for diagrams and photos on the Net in addition to the manuals I have been able to find…that don’t offer much detail.

My mind wanders - and think about putting together a book on how to assemble these… but…”from a cost and fabrication perspective” I may end up homeless and broke - only to find myself in retirement, disheveled more than I normally allow, and holding out a cup at the entrance to antique truck shows.

Look at this photo of a 1946 GMC. Notice the V Brace and the bracket at the firewall which your truck is lacking. It looks like each side has one of those bars.

https://www.barrett-jackson.com/Events/Event/Details/1946-GMC-1/2-TON-PICKUP-130321

Here's another 1946 GMC that has the same bar/bracket that the V Brace rods pass through and obviously keep it from sliding in and out of the firewall.

https://topclassiccarsforsale.com/chevrolet/82148-1946-gmc-truck.html

From close examination, of the photos, I'd hazard a guess that your brace is not correct for the vehicle. Your V brace lacks the bends just before entering the firewall.

Also, is that a PCV system on the engine in the picture below?

I tend to think you are right, Otto. All three braces I have are not correct. I may need to heat, straighten, thread, and bend the rod after-all. Thank you for posting these pictures.

Yes, the GMC’s did come with a factory PCV system. Not all engines had them. I have had them on both civilian and military 270 and 302’s, and yet, perhaps big truck applications used them. I have also had 2-3 GMC 228’s that did not have them. A later 270 only had a standard vented cover, and I have seen 228’s with them too. I can’t say if these were used throughout their production or limited to certain years or applications.

Thanks again. You and Paul have been very helpful.

Tom