3-Point Hitch Top Link Bracket Positioning

[Jack3489]

Tom, I've read the history of 3 point development in England and that the original concept used draft control to lessen the impacts of plowing on the tractor. However, many "modern" tractors (like my two) have a fixed 3 position top bracket with float implement positioning control (thus no interactive draft control). Guess I'm still puzzled regarding the theory behind which position to use on these modern fixed brackets.

I certainly understand that the top link is typically in a compression mode when using heavier ground turning implements and that this compression assists with traction by putting pressure on both the rear and front wheels. I assume the angle between the top link and the implement determines how much force is produced.

I'm still surprised that we (as a collective group of experts) have not been able to find any definitive link that details the concept / theory. I keep looking!

Thanks again for everyone's input.

Jack

 

[Dan Hunter]

From my jd 3720 manual:

• For light and medium draft loads: Install center link (A) in bottom hole (B) of mounting bracket. Example of light and medium draft load implements would include a landscape rake.

• For medium and heavy draft loads: Install center link in middle hole (C) of mounting bracket. Example of medium and heavy draft load implements would include a tiller or box blade.

• For very heavy draft loads: Install center link in top hole (D) of mounting bracket. Example of very heavy draft load implements would include a plow or ripper.

 

[bandaidmd]

Interesting discussion but no real answer yet. To muddie up the replys why do tractors that dont have draft control still have 3 holes and Dans manual has it completely backwards from the other posters manuals.

 

[RoyJackson]

Interesting discussion but no real answer yet. To muddie up the replys why do tractors that dont have draft control still have 3 holes and Dans manual has it completely backwards from the other posters manuals.

It's a matter of stress loads on the tractor...

 

[RoyJackson]

Interesting discussion but no real answer yet. To muddie up the replys why do tractors that dont have draft control still have 3 holes and Dans manual has it completely backwards from the other posters manuals.

It's a matter of geometry and stress loads on the tractor. Different tractors have different upper link bracket locations.

 

[Jack3489]

I agree this is a great discussion.

During my research I've also noticed that John Deere and Kubota manuals are diametrically opposed to each other in their recommendations! In theory, they should be the same (for the principles of physics do not change). The angle between the tractor and the implement is the driver of force. The different approaches between John Deere and Kubota make no sense!

Does anyone have else have a manual for a different brand that they can reference?

Jack

 

[duroc]

Does anyone have else have a manual for a different brand that they can reference?
Jack

From my NH T1510 manual..

"The hydraulic lift rocker has two holes for attaching the upper link. Attach the link using the lower hole for light draft loads, such as mowers. Attach the link to the top hole for heavier draft loads, such as ground engaging equipment."

 

[94BULLITT]

From my jd 3720 manual:

• For light and medium draft loads: Install center link (A) in bottom hole (B) of mounting bracket. Example of light and medium draft load implements would include a landscape rake.

• For medium and heavy draft loads: Install center link in middle hole (C) of mounting bracket. Example of medium and heavy draft load implements would include a tiller or box blade.

• For very heavy draft loads: Install center link in top hole (D) of mounting bracket. Example of very heavy draft load implements would include a plow or ripper.

That is what my Kubota manual says and my Bobcat manual also said that.

 

[Jack3489]

Roger, guess there is even a difference between Kubota models. My owner's manual for the L3800 says to use the bottom hole of the positioning bracket for "earthmover, digger, scraper and moldboard plows." It only says to use the top hole for "light soil" conditions. Appears to be totally contrary to your Kubota manual.

The mystery continues.

Jack

 

[94BULLITT]

Roger, guess there is even a difference between Kubota models. My owner's manual for the L3800 says to use the bottom hole of the positioning bracket for "earthmover, digger, scraper and moldboard plows." It only says to use the top hole for "light soil" conditions. Appears to be totally contrary to your Kubota manual.

The mystery continues.

Jack

I looked at the 4240 manual. I was wrong. Bottom holes for heavy draft work. I can't use the bottom hole. I usaully use the middle hole. My top link hits the PTO shield. Maybe I should remove for non PTO work.