John Deere 850 tractor, what is this control for?

[m5040]

Can anyone shed some light on what the hyd control under the seat is for on a John Deer 850? It is the one with a rollpin in a shaft, looks to adj flow or???

 

[Barry 1]

That is the rate of drop valve. Put something heavy on the three point hitch,and adjust that valve so it drops slower when you lower it.

 

[m5040]

That is the rate of drop valve. Put something heavy on the three point hitch,and adjust that valve so it drops slower when you lower it.

If that is the rate of drop control, what is the large flower shaped knob in the lower left corner of the 1st picture for?

 

[Sheldon Hamblin]

If that is the rate of drop control, what is the large flower shaped knob in the lower left corner of the 1st picture for?

I had an 850 for 27 years. The “flower” shaped knob is the rate of drop for the three point. The lever you are referring to is the draft (at least according to the owner’s manual I had)

 

[Barry 1]

If that is the rate of drop control, what is the large flower shaped knob in the lower left corner of the 1st picture for?

The one with the knob is the Stop valve which you would use if you wanted to lock the three point hitch up.I never have found a use for it yet,so always leave it unscrewed all the way out. the book says Important: 1. Do not raise control lever when hydraulic stop valve is closed. 2. Do not lock rockshaft in its highest position. 3.Open valve completely when it is not in use.

 

[joecdeere]

See if this helps-

 

[m5040]

Thanks for all the responses. So much for standardization as all my other tractors the flower knob was rate of drop. Now I know it is the hard to get to roll pin!