These were only used on Trucks with Automatic Transmissions. I would guess the reason they were used was to prevent damage  to the kickdown linkage used only on Automatic Transmissions.

  

I think you have something.
So should it be adjusted so it touches the gas pedal (carb fully open) with the plunger fully depressed?
The truck came with a Fordo. and it may be a physical indication with something related to its operation?
Many Thanks for all replies.
Stay safe
stuey

 

Thanks for reply. There are no terminals for wiring connections.
stuey

Funny Ha - Ha.
Nice to see a sense of humour in these trying times.
Actually it does not do anything which is what's so perplexing.
stuey

Its called a Detent Stop. Should be adjusted so it just touches Gas Pedal when Carb is fully open. Limits the Pedal Linkage travel.

  

Sounds like the kick down cutout switch for overdrive.

  Dennis in Lititz PA

Does it go "Ding-Dong" when you push it?

"FREE SAMPLE"

Hi folks
    Under the accelerator pedal in my 56 F100 there is a device that I believe to be a pedal stop.
It has a sprung loaded plunger on top with about 3/8" travel.
Part number 9A858.
What's the purpose of the plunger?
There are no electrical connections.
Thanks
stuey