John Deere 2120 3PT Hitch Raises up on its own?

[bigblock76]

Does anyone know why the 3 point links would slowly raise up under no real load? If I'm using the snow blower or bush hog and never look back I wouldn't be doing much of any work because as I drive, the links slowly rise up and I constantly need to lower the lever again to bring them it back down.

Not sure if this is related or not, but when I just the tractor off and if I had the arms raised, they will drop down in the matter of 10 mins.

Has anyone heard of this one before?

Mark

 

[jd110]

It sounds like you might have 2 separate problems. If the hitch rises on it's own and the control lever is rising also, you have a problem with the friction washers on the lever not working right. There should be 3 flat washers there with 2 spring washers sandwiched between the flat washers that acts as a "brake" to hold the lever in position.
For the hitch leaking down quickly, you probably have worn or blown seals in the rockshaft valves and piston. The rockshaft housing needs to be removed to access those.

 

[EMcPhee]

When the tractor is shut off it will decend as the pressure is relieved. I put it down any ways to relieve the strain on the rockshaft-- call it setting the anchor.

 

[bigblock76]

It sounds like you might have 2 separate problems. If the hitch rises on it's own and the control lever is rising also, you have a problem with the friction washers on the lever not working right. There should be 3 flat washers there with 2 spring washers sandwiched between the flat washers that acts as a "brake" to hold the lever in position.
For the hitch leaking down quickly, you probably have worn or blown seals in the rockshaft valves and piston. The rockshaft housing needs to be removed to access those.

Yes, as the links rise, the lever rises also. From what you are describing, I should be looking at #10 & #11 on this diagram to correct it? Sounds easy enough.

As for the links lowering as the tractor is shut off. I'm assuming it shouldn't drop in a matter of minutes at best. Sometimes I raise it and want to keep it raised so I can work under the bush hog, clean the deck for the end of the season type of thing. Yes I do support it with blocks so I am not relying on the tractor for safety while I work on it. But it drops at a fast rate which doesn't seem normal.

How hard is it to change the piston o-rings? Once the seat comes off, then what?

Mark

 

[Tx Jim]

bigblock76
On 3 pt lowering when engine is stopped with 3 pt raised,engine running look inside hyd filler hole for spraying oil. JD utility tractors such as yours have a history of the control valve o-rings leaking. It's also possible the control valves are adjusted too tight which adjustment can be altered without removing RS housing.

 

[bigblock76]

bigblock76
On 3 pt lowering when engine is stopped with 3 pt raised,engine running look inside hyd filler hole for spraying oil. JD utility tractors such as yours have a history of the control valve o-rings leaking. It's also possible the control valves are adjusted too tight which adjustment can be altered without removing RS housing.

Hi Tx Jim,

Where is the adjustment so I can check it? Can it be done without removing the seat cover?

Mark

 

[bigblock76]

bigblock76
On 3 pt lowering when engine is stopped with 3 pt raised,engine running look inside hyd filler hole for spraying oil. JD utility tractors such as yours have a history of the control valve o-rings leaking. It's also possible the control valves are adjusted too tight which adjustment can be altered without removing RS housing.

I do lower them when I shut the engine off, but the reason I want to chase this is because I feel that I am losing pressure and its also nice to keep the bush hog up to service it sometimes.

 

[Zebrafive]

I found changing the "L", "LD", and "D" lever makes a difference in the 3pt raising on its own. I just don't recall where I ended up setting mine.

 

[Tx Jim]

Hi Tx Jim,

Where is the adjustment so I can check it? Can it be done without removing the seat cover?Mark

IIRC you need to remove plug(parts key #14) in RS housing to access adjusting screw(parts key #9) on linkage.

 

[bigblock76]

IIRC you need to remove plug(parts key #14) in RS housing to access adjusting screw(parts key #9) on linkage.

Hi Tx Jim,

What result should I expect to change by turning it in vs turning it out so I can figure out what to look for when I adjust it?

Mark