C-120 Auto speed control friction problem

[Sailman 1,299]

I have 2 C-120 auto's that I bought recently and am using as workers. Both had very loose speed control levers. On one tractor I tightened up the collar friction adjustment and it worked great. The other...not so much.

Had to use some PB Blaster to get the adjuster to move (lock nut was free) on the second tractor. Seems no matter which way I adjust the 5/8 threaded portion it does not tighten up and create the tension or resistance I need to keep the speed control lever in place. Have to literally hold the lever while running the tractor.

Any suggestions on how to correct this issue???

[daveoman1966 3,841]

My bet is that the WELD on the Friction Control ROD is broken.  Look at the TAB on the left side of the Hoodstand...   is the weld cracked/broken.  

[Sailman 1,299]

Looks like the weld may have a slight crack. Hard to tell. What is the fix? Grind it down a bit and reweld? What is the weld holding? When I look inside that area it doesn't turn when I turn the 5/8 bolt. Seems solid.

Also look at 2nd picture. Looks like the threads are not connected to the adjustment area with the spring. Is that correct? Seems like 5/8 bolt just turns without moving the spring area. Is there a fix for that?

Thanks for the help!!

[pfrederi 18,714]

Looks like your threaded portion backed all the way out of its retainer yellow circle.

 

 

 

[Sailman 1,299]

I think you are right. That appears to be the issue. Will try some clamping on the locking nut and square frame to see if I can pull the threads into the collar. Suspect it needs to compress the spring some to get the threads started. Will try it tomorrow. Thanks!

[Sailman 1,299]

I can't seem to get the threaded part to budge any closer to the retainer to start the threads. Part just turns and turns but does not move closer to retainer. Can I disassemble the parts by removing the bolt on the left side of tractor and pulling the welded tab and rod out the left side? There seems to be something broken or blocking the threaded portion. It appears like the rod goes all the way through the friction control hardware, so wondering if I can disassemble it. Anyone have experience with this problem? Doesn't seem to be a broken weld.

[WildmanC120 613]

Are you missing the key that goes in the center rod?  If so you won't get it to tension.

 

Also where the friction cup comes together with the flat piece I have circled. If they slip and do not move together you won't get tension.  I have welded them together to fix that issue before.  

 

 

[daveoman1966 3,841]

These are the components of the Friction Control of the Auto tractors:  If that tiny little WOODRUFF KEY is missing or damaged, the apparatus won't work right.

[Sailman 1,299]

Thanks for the diagrams and info. There is no slippage at the friction cone but its because there is no movement against the tension spring or threaded guide. The hollow tube is outside of the threads in the threaded guide ( circled in red) and will not slide closer to the threaded guide. Even applying leverage against the locking nut and right side housing...no movement.

Any ideas why the hollow tube doesn't simply slide up to the threaded guide where it could start the threads?

I am wondering if the hollow tube was somehow buggered on the end of the housing next to the drive belt keeping it from sliding freely. (yellow circle) Any thoughts?

If I take it loose at the locking tab would I be able to pull it out enough (up to the woodruff key) to maybe engage the threads and then try to work the shaft back in?

Any manuals on how to correctly disassemble the whole unit like your diagrams?