Another 3 point hitch question

[etpm]

Greetings All,
Even more questions. The sheet metal where the 3PH control lever comes out of has 2 slots. One slot is empty. My manual says nothing about this empty slot nor does it mention 2 controls for the 3 Point Hitch (3PH). But under this sheet metal are two things that have something to do with the 3PH. One is a rod that has a coiled spring around it and the other is a lever with a small hole drilled through the end. The rod with the spring is connected at one end to one of the 3PH arms. The other end is connected to a short bell crank arm. This bell crank has two arms and pivots about a rod that is located under the sheet metal with the two slots. Anyway, the rod/spring combo is connected to the short inboard arm and the other bell crank arm is the lever with the small hole drilled through it described above. The lever can only be moved easily in one direction and moving this arm lowers the 3PH. The lever also moves when the 3PH control lever is moved.
So, after that long winded description does anybody know why there are two slots? Is the tractor missing some linkage? I'm sure the lever with the small hole and the rod with the spring has something to do with controlling the position of an implement attached to the 3PH, but don't know how it works. I wish my owners manual mentioned this linkage.
Anyway, any help would be greatly appreciated.
Thanks,
Eric

 

[ptsg]

The reason for the 2 slots is that one is for the Position control lever, the one you use to control the height of the 3 pt. The other is for the Draft control lever, usually used when plowing a field, however, Draft control is not offered in the US market for pretty much all manufacturers up to probably 75HP. I don't know exactly the limit for that.

The linkage you see underneath is part of the Position control. Basically it gives position feedback to the control valve, so it knows exactly where it is and can compensate if needed.

 

[Smokeonthewater]

My 73 yr old 25 hp ford has draft control

 

[ptsg]

My 73 yr old 25 hp ford has draft control

Yeah, I should really have mentioned the newer stuff.

 

[bmaverick]

My 73 yr old 25 hp ford has draft control

The John Deere 50 Series siblings to the Yanmar YM Series, offered as an option Draft Control. So yes, machines from the 20Hp-ish range on up are capable. This would include the OPs YM2310.

Draft control also helps with snow removal and a rear blade too.

 

[oosik]

The second slot was surely designed for draft control. I have draft control on my 2009 Kubota M6040. I would trade draft control for a second set of remote control valves - in a heart beat.

I've used it when plowing with my single bottom moldboard plow. I have so many rocks - draft control really never gets a chance to work.

 

[LouNY]

I've operated tractors with draft control since we got the Farmall 400 back in the 50's.
I've never been impressed with it. When plowing if I hit a tougher patch of ground and started to pull the tractor down I would rather use the (IH's) TA or drop a gear normally I have found that my limiter was traction and draft control doesn't function to reduce the load if you break traction and end up with less pulling force. For the draft controll to function you have to have a traction and power reserve. As the load the 3 point is seeing increases above what the draft control setting is it will raise the implement to reduce the required pull as the required pulling force decreases it will lower your implement to the preset position control.
With a back blade positioned using the position control with the draft control enabled it would raise the blade if the pulled load increases above the setting and lower it when the pulled load decreases, back to the original set position.

 

[ponytug]

I think it might depend on the task. I happen to like draft control for brush hogging on my Power-Trac. It sets the pressure in the lift circuit and moves more weight to the tractor tires and makes slope mowing much more stable. I guess I have always viewed it as weight distribution tool rather than a force tool. That said, I don't use it for anything else.

I can see that plowing in rocky soil with draft control wouldn't work particularly well, at least with all of the draft controls that I have used.

All the best,

Peter

 

[Smokeonthewater]

A few years back I was running a big over 200 hp john deere 4x4 on a pipeline job... can't remember the model (thinking 7215) but it was big enough to have a passenger seat in the cab... mostly I was discing w it but at times I ran a big subsoiler DEEP... and found that if I set the draft control just right it made it a little easier to keep the front wheels at least close to the ground, but if I set it wrong it made em come up fast and suddenly slam down when the draft control yanked the subsoiler out of the ground....

Fun stuff