YM276D 3-Point Question

[richriddle]

On the YM276D above the Power Take Off (PTO), the top link assembly has a large spring assembly I have not seen on other tractors like Kubota. What is the purpose of that large spring related to the top link?

 

[winston1]

It is called a sensing spring for the draft control.

 

[rScotty]

It is called a sensing spring for the draft control.View attachment 661681

Just as Winston says...That pivoted top link mount is the sensing mechanism for automatic draft control. Draft control automatically raises a 3pt implement if it runs into an obstruction to forward motion.....like if a plow if it hits an obstruction underground. Auto Draft control is an optional accessory on most farm tractors of that size and up. It's the automatic version of manual draft control - which is just the operator with one hand on the 3pt lift mechanism and constantly adjusting the plow or blade depending on the toughness of the substate and whether there are any rocks.

Draft control is actuated when anything makes the 3pt implement harder to pull through or across the ground. When pulling gets tough, the pulled implement tries to pivot forward and in doing so it puts the top link under compression. The spring & pivot mechanism of the top link mount determines how much compression it will take to actuate draft control. As that mechanism is compressed, it opens a valve to the hydraulic system and feeds a bit more fluid to the 3pt lifting piston...lifting the implement just a touch.

Take a look at yours and you will see several holes that the top link can be mounted in. Mounting closer to the mount's pivot point decreases the sensitivity of the draft control.

When the control actuates, it very quickly raises the implement in a series of small jerks until the top link is no longer in compression, and then it bleeds off the pressure holdng things off over a slightly longer period of time. So the plow or whatever returns to its original position.

There are times when you don't want automatic draft control. An example is when using a 3pt backhoe. So there is a control to turn it off. Used with a 3pt backhoe the auto draft control can become a literal killer if it lifts unexpectedly and pins the operator against the back of the tractor.
rScotty

 

[AV8R]

Just as Winston says...That pivoted top link mount is the sensing mechanism for automatic draft control. Draft control automatically raises a 3pt implement if it runs into an obstruction to forward motion.....like if a plow if it hits an obstruction underground. Auto Draft control is an optional accessory on most farm tractors of that size and up. It's the automatic version of manual draft control - which is just the operator with one hand on the 3pt lift mechanism and constantly adjusting the plow or blade depending on the toughness of the substate and whether there are any rocks.

Draft control is actuated when anything makes the 3pt implement harder to pull through or across the ground. When pulling gets tough, the pulled implement tries to pivot forward and in doing so it puts the top link under compression. The spring & pivot mechanism of the top link mount determines how much compression it will take to actuate draft control. As that mechanism is compressed, it opens a valve to the hydraulic system and feeds a bit more fluid to the 3pt lifting piston...lifting the implement just a touch.

Take a look at yours and you will see several holes that the top link can be mounted in. Mounting closer to the mount's pivot point decreases the sensitivity of the draft control.

When the control actuates, it very quickly raises the implement in a series of small jerks until the top link is no longer in compression, and then it bleeds off the pressure holdng things off over a slightly longer period of time. So the plow or whatever returns to its original position.

There are times when you don't want automatic draft control. An example is when using a 3pt backhoe. So there is a control to turn it off. Used with a 3pt backhoe the auto draft control can become a literal killer if it lifts unexpectedly and pins the operator against the back of the tractor.
rScotty

Yes. I have been looking for what specifically was on my 2610. It has a small lever you. If I need to raise more on my three point. I can pull this and make the implements higher. I need this for heavier implements like my Bush Hog.

 

[winston1]

Yes. I have been looking for what specifically was on my 2610. It has a small lever you. If I need to raise more on my three point. I can pull this and make the implements higher. I need this for heavier implements like my Bush Hog. View attachment 661758

Now that is interesting, a first for me. That would appear to be a feedback rod adjustment that regulates just how far your lift will come up.

 

[AV8R]

Now that is interesting, a first for me. That would appear to be a feedback rod adjustment that regulates just how far your lift will come up.

Here is a side shot:

 

[richriddle]

Thanks for all the information. I asked because the ROPS for the YM276D would require one to remove the automatic draft control spring system. I shall figure out a way to have the ROPS welded since it sounds as though the automatic draft control system is a good thing to have.

 

[rScotty]

Thanks for all the information. I asked because the ROPS for the YM276D would require one to remove the automatic draft control spring system. I shall figure out a way to have the ROPS welded since it sounds as though the automatic draft control system is a good thing to have.

Instead of ROPS, consider the gain in initial safety by setting the rear wheels out wider. But if you really need a narrow base tractor then ROPS might help. Although if you plan to do the kind of work where a ROPS is necessary, there's a better option in a 4 post with a canopy top.

If you do much pulling of ground-engaging implements in tough ground - and want to reduce tire spin - then auto-draft control does some of the 3pt control work for you. For that I would keep it. It actuates faster and more precisely than a person can.

I haven't done much of that kind of work in the last 50 years, but for a mostly retired hobbyist like myself, it's interesting to feel the draft control actuate when the back blade hangs on a rock. Draft control may be no necessity, but then that's sort of what a hobby is all about.
rScotty