throttle linkage sticking???

[rickyrecon]

I'm not sure of the problem - perhaps it is simply my throttle linkage sticking? Often when driving and hitting the accelerator, the engine revs up to maximum RPM's and won't decelerate when I take my foot off. I have to jump into neutral. The accelerator linkage looks ok - but it sticks.

What should I be doing? It's definitely a safety hazard.

Thanks for any advice
Ricky Recon

 

[Jbulach]

I’m assuming your working on a M939? Check and lube the hinge pin on the accelerator pedal, they are notorious for freezing up with lack of use.

 

[M813rc]

Ditto on the above.

After checking all the complicated stuff, I realized it was the pedal hinge itself sticking on my M931 (which was being driven regularly). Lube didn't help, the pedal ended up stuck solid.
I replaced it with the pedal out a parts 1966 M35, bolted right in and it is still as free as it was new 50 years ago!
If you don't have access to a spare, I imagine your pedal could be taken apart and refurbed. I didn't bother trying with mine.

Cheers

 

[allie]

Ditto on the above.

After checking all the complicated stuff, I realized it was the pedal hinge itself sticking on my M931 (which was being driven regularly). Lube didn't help, the pedal ended up stuck solid.
I replaced it with the pedal out a parts 1966 M35, bolted right in and it is still as free as it was new 50 years ago!
If you don't have access to a spare, I imagine your pedal could be taken apart and refurbed. I didn't bother trying with mine.

Cheers

im having same problem with my 1986 M931 tractor where should i start? i guess ill need to see how it comes apart thanks

 

[M813rc]

I'd say start with the pedal itself, I've since heard that the hinge point sticking is fairly common on the 939 series because of the spray liner on the floor of these trucks. Mine got sticky, as in was slow to return or had to be pushed back up with a boot toe, then froze solid one day. Since I had access to a pedal from an old M35, I just swapped mine out (they're identical), but if you want to keep the original pedal, the pin can be removed and the offending crud cleaned from it and the pedal. On some pedals I've looked at, the hinge pin is a one-time use pressed-on thing, and you might have to find a replacement bolt or pin to use.

If it's not the pedal, then move on to return springs, the linkage, and work your way up the system until you find the sticky bit. Most of it is pretty simple and easy to get at.

Cheers

 

[allie]

I’m assuming your working on a M939? Check and lube the hinge pin on the accelerator pedal, they are notorious for freezing up with lack of use.

do i need to take the pedal off i guess ill see when i get to it thanks!

 

[Jbulach]

do i need to take the pedal off i guess ill see when i get to it thanks!

No, unless it’s frozen solid. Just use your favorite penetrating fluid and thoroughly spray the hinge point where the aluminum pedal, pin and steel floor bracket meet. Then start working the pedal while periodically spraying with lube. If it’s really bad, unhook the linkage so you can pull the pedal further back toward you. It should free up quickly, just lube it every once in a while in the future, especially if the truck sits for long periods of time, or wet with road salt from your boot’s.

 

[allie]

No, unless it’s frozen solid. Just use your favorite penetrating fluid and thoroughly spray the hinge point where the aluminum pedal, pin and steel floor bracket meet. Then start working the pedal while periodically spraying with lube. If it’s really bad, unhook the linkage so you can pull the pedal further back toward you. It should free up quickly, just lube it every once in a while in the future, especially if the truck sits for long periods of time, or wet with road salt from your boot’s.

great ill do it! yes it sits mostly

 

[M35A2-AZ]

Make sure it has the return spring on it.