Info needed: F60S progress - accelerator linkage

[Alastair Thomas]

Thanks everyone for the information. I have been looking at the wrong page for the answer hence my late acknowledgement.
The picture gives me a problem however. Nearby here is a F60S LAAT and I took the opportunity to look at its linkage and the upper arm on the cross link is much shorter than the one in the photo. This seems to me to be logical as the travel at the carburetter is limited to about one and a half inches so such a long arm as is shown would surely risk bending the carb linkage.
I have been working on similar triangles and lengths of arm from the pedal onwards and this would seem to confirm my impression.
I might add that the truck is in "well used" state and that I can see that a number of things are non-original.

[Jacques Reed]

Hi Alastair,

As per attached photo: The arm in question has to be fairly long to clear the HT lead conduit. Any shorter and it would foul it.

Travel of the throttle plate arm can be limited to prevent bending anything by a bolt that screws into the back of the accelerator pedal (this bolt I usually find missing but you can see the tapped hole for it on the backside of any pedal at the top).

It is listed in the parts manual as part No. 20368-S7, Bolt- Accelerator stop, 3/8-16 x 7/8" (3/8 UNC 7/8" long) There is also a nut listed for it as 33927-S2, Nut- Accelerator pedal stop bolt. Surprisingly it is then shown to be 7/16-20 Hex check. Don't think a 7/16" nut will work very well on a 3/8" bolt although I believe I have seen attempts of similar things at times!

Hope this is of some help.

[Tony Smith]

The length of the upper arm from the axis is about the same as the length of the lower arm, so the ball would only move the same amount as the throw of the "Toe board" ball.

[Jacques Reed]

Hi Alastair,

Further to discussion here is the setup I did on a spare accelerator pedal I have. One picture worth a thousand words.

I used a 3/8 UNC x 1" bolt instead of the 7/8" long one as specified. Didn't have a 7/8" long one. The check nut is obviously a 3/8 UNC not a 7/16 UNC as specified in the parts book.

check nuts can also be referred to as half-height nuts which is what I have here.

Also the initial position of the pedal can be set by the adjustment on the pedal rod. Note the half-height check nut on it. Between that adjustment, and the stop bolt, you should be able to do pedal to the metal without bending any of the linkage rods or arms or carby shaft.

Hope this helps.

Cheers,

[Alastair Thomas]

Thanks everyone. I will go ahead and make the necessary links and control the overall motion as you suggest.