The Stovebolt Site Forums The Shop Area Paint and Body Shop Radiator support to frame spacing? - 1950 GMC 1/2 ton

Can anyone help with this - I can't finds any specs in the 1948-51 Maintenance Manual or searching this forum:
What is the normal clearance between the bottom of the rad support and the frame cross member?

My 1950 GMC 1/2 ton is "well used" and the supporting bracket that normally fills that space has completely worn through the metal of the radiator support (large U shaped frame), so the rad frame is sitting on the frame cross member and just bouncing loose.
The manual shows a picture of this - called the Stabilized Front End Mounting - photo attached
It lists clearance for the Cab Front Corner Mounting as 1 53/65" to 1 57/64" - pretty close tolerance for a rubber mount gap . . .
But I can't find a similar clearance for the front end mounting.

Comparing the photos, it looks like the gap should be around 3" ?

I will have to make a plate to cover the huge hole in the rad support, and then rig some sort of holder for a rubber cushion.

Thanks for any help

Jim

PS - just completed installing new motor mounts, new clutch, less broken 3 speed tranny, and new Okie torque tube bushing.
So far so good.

But now the engine is sitting a bit higher than it used to, and the cab is rubbing on the bell housing.
I'll put in new cab front corner rubbers, and then something to lift that front end.

As a Canadian GMC, does it have a Chevy engine and perhaps a Chevy front crossmember as well?

I does have the 216 engine - which I understand is the same as the US Chev 1/2 ton

Update - here is a photo after lifting and blocking the front end.
The spacing looks about right with a 1" gap - but you can see the wreckage - it is hard to tell what it really should be.
Is anyone able to have a look at their 1950 Chev 1/2 ton and measure what you have.

Thanks for any help you can offer.

Jim

I just went out ANd measured mine. It's 23/32" exactly

Board slides in snugly without force and without wobbling loose.

Board is 23/32" thick according to Home Depot.

11/16" is probably close enough

Hey Otto, thanks for taking the photos and measurement - that is exactly what I need.
Jim

Jim,
If you look closely at your factory diagram there is some sort of padding between the radiator support and cross member. That is missing in Otto's picture and I suspect the spacing is more like one inch, at least. You need to have rubber or fabric padding to prevent metal on metal contact (reduce noise and wear).

For what it is worth, my '51 Chevy half ton has a spacing of 1 1/4 inch. The design is different with two contact points that have the same design as the single point depicted above. And there is substantial rubberized fabric padding.
Kent

Thanks Kent - how far apart are the two contact points ?
I read somewhere that the single contact point was only in production for a few years,
though it was advertised as being superior to the competition at the time.

I need to rebuild mine, and it seems a modification would be in order.....
Jim

Interesting. Does the rubber pad sit under those two U shaped pieces? How is it fastened in?

How do you separate the support from the frame to install the rubber?

The two supports on my truck are 7 3/4" center to center

On my truck the supports are also 7 3/4" center to center. The pads have a central hole for the support bolt.

You could make your own out of truck mud flap or similar material or order from various vendors
https://oldchevytrucks.com/me195.html

I am sure at the assembly plant the rolling chassis had the pads installed with the radiator. Later the front sheet metal would be placed. Since everything is connected, to install in an completed truck I think you would have to loosen all the bolts on the front end, remove the mounting bolts and pick up the shroud with a bar or jack.
Kent

The FAM dimensions call out 8.0 inches center to center of the 7/16 x 11/16 slots in the front crossmember for the two bolt radiator support mounts.
Here's two photos from the FAM. Interestingly enough, the two bolt mounts don't indicate any cushions, but the single bolt mount does, unless the 378516 SHIM and 2692225 BODY SHIM are made from rubber. Note that the center support has a threaded plate for the two bolts from the bottom, while the two bolt support uses carriage bolts inserted through the top, with nuts on the bottom.

I'd almost be inclined to modify the radiator support for the wide spaced mount. The FAM indicates that it has cross bracing rods, while the center mount radiator support has no cross bracing. It wouldn't be hard to add those with some 1/4" steel rod welded in.

Thanks Kent for the link to purchase the pads - the info lists them at 3x2x1 - so I guess 1" thick - that really helps.

Kevin - the FAM looks like a great resource book - where did you get yours? Do you know if it is available on line?
For the single center mount like mine, it lists the pad shims "as required" - which comes back to my original questions - what is the required total gap - do you see that listed anywhere?

Thanks for your help

Jim

The FAM is available from most of the vendors or from Amazon. Link
As far as how many shims are required, it depends on how everything goes together to get things lined up correctly. I'll be looking at that after this winter when I start putting my truck back together.

Thanks Kent. Have fun with your project - the photos look great. I'd be interested to hear what you finally come up with for that spacing.
It seems odd that there is a very precise spacing tolerance for the front cab mounts, and no gap and tolerance listed for this - just shim as required.
I made a temporary fix that leaves a 1 1/8" gap that looks ok.
Jim