Throttle return spring

[sammon287]

My father's '54 M-37 has the incorrect throttle return spring and we would like to change it back to the factory design. He ordered the correct spring, but it is unclear from the exploded diagram where the spring extension attaches to. I assume it is somewhere on the firewall. Someone hacked a hole for what I assume is a non-standard heater core and I'm not sure what other changes have been made over the years. Can anyone advise where the spring attaches to opposite from the carb linkage (the hook at the end of part X)? Should there be a floor plate bolt with a lateral hole in it?

 

[sammon287]

Also, is the extension available anywhere or do we need to make one? I'm not sure how long it needs to be.

 

[Canadianz]

So I went out to the shop to take a picture, only to realize that I don’t have the correct throttle return spring either. However, this should show you where it is attached. It fits into a hole on the lower lip of the cab, near where the transmission pan bolts up. At least, that’s where the farmer fix on mine is attached!

 

[G744]

That is right. Overly simple...

 

[sammon287]

The photos are very helpful. Thanks for posting them. I didn't see that protrusion from the firewall. Is the hole in a rolled edge next to the center panel? I thought it was supposed to be attached to one of the floor plate bolts with a lateral hole in it, but that was for something other than an M37, maybe a WW2 Jeep. It was on a Power Wagon forum, but it came up when I searched "M37 throttle return spring".
It looks like you have a longer spring without the extension piece. Since he ordered the correct spring, we'll have to fabricate the extension and create an attachment point if that factory hole isn't there anymore.

 

[ab705]

This diagram from TM 9-2320-212-34P doesn't show the attach point for the spring, but perhaps it could be of some use.

Items 11 and 12 are listed as:
FSN 5360-536-2617, Spring, Helical Extension: accelerator pedal return 7001073 (19207)
FSN 5340-832-7929, Extension, Return Spring: accelerator pedal 8327929 (19207)

 

[Black Ops]

This one doesn’t have the correct spring but shows where the hole is in the panel.

 

[sammon287]

This one doesn’t have the correct spring but shows where the hole is in the panel.

That section of metal with the hole appears to be missing on my father's truck. It just looks like it was trimmed off right to the hole for some reason. We will have to make the spring extension and some way to attach it. Shouldn't be too hard. I appreciate the photos just so we know that doing it like the factory did isn't an option anymore.

 

[ab705]

One more photo of the accelerator return spring attachment hole for your viewing pleasure.



If the flange with the hole is missing, you should be able to easily make a little bracket that can be attached in the same location. Before you try making a spring extension, see if you can find the NOS spring parts:

FSN 5360-536-2617, Spring, Helical Extension: accelerator pedal return 7001073 (19207)
FSN 5340-832-7929, Extension, Return Spring: accelerator pedal 8327929 (19207)

I would NOT suggest attaching the spring in a different location, as it could change the geometry of the system.