M-38 Body Mount Question...

[Jordan]

Gentlemen:

I just set my newly painted M-38 body on my frame. As you all know, the hat channels on the left and right side extend forward under the firewall. There is a vertical bracket (stamped gusset) that extends vertically from the hat channel to the firewall on each side. Each of these hat channel extensions has a hole in it, suggesting that a mounting bolt is supposed to go down through the hole (on each hat channel extension) into the frame. But there is no corresponding hole in the top rail of the frame. Is the hole in the hat channel simply to assist in lining things up before spot welding the hat channels? There is a stamped bracked which extends downward from the vertical gusset on each side of the frame and a bolt goes though that bracket into the side of the frame. That much is clear, but curious about the hole in the end of each of the hat channels and no corresponding hole in the frame.

Thanks,
'

Jordan

[Bretto]

I was told that those holes along with the holes under the side steps were there to assist in assembly in the way of alignment.

[rgmutchler]

If I understand the location you are talking about, there should be a bracket at 90 degrees to the hat channel that bolts to the outside vertical part of the frame.

[Jordan]

Thanks Brett!

[Jordan]

If I understand the location you are talking about, there should be a bracket at 90 degrees to the hat channel that bolts to the outside vertical part of the frame.

Yes RG, that is what I have. Apparently then, it is this vertical straps, left and right that holds the body down at the front and the vertical holes in the front ends of the hat channel are there simply to assist in aligning the hat channels for welding.

[wesk]

The vertical extensions you are describing are called toeboard gussets.


A rubber isolator pad goes between the horizontal extension of the floor hat channel under the toe board gusset and the top of the frame rail. A bolt goes between the frame and the side bracket which is bolted to the side of the frame. If there is a gap to fill between this side bracket and the side of the frame rail fill it with a rubber pad.







We have not found any supporting data for the purpose of the hole in the front end of the toeboard gusset and the front end of the hat channel. We have not yet found any supporting data on why the bolt is used only on the side bracket. However if I was asked to offer up a theory I would say to ensure that the height of the firewall relative to the frame stay fixed to ensure the proper continued alignment of the starter kick pedal.

[Jordan]

That photo shows the whole arrangement.