John Deere 440b

[pabarhunter]

Hey Guys, Merry Christmas to all. Just got a 440b, put the chains on, cut some firewood this morning. The previous owner told me that the blade tends to creep up. Getting wood this morning it did just that. Anyone else heard of this problem or have any ideas of the cause? Thanks, jim

[beenthere]

Blade creeps up when?  just sitting and idling? or when running the trail? or ??

[pabarhunter]

Beenthere, the blade creeps up at idle, or running up a trail. If the engine is running it will creep. Blade works fine otherwise. Didn't like it much sitting on the sidehill today watching the blade creep up.

[Autocar]

I have never seen one go up but I would think that hyd. oil is forcing it's way around the spool on the vale bank and just like activating the spool with the handle oil makes her rise.

[pabarhunter]

Autocar, I have never had the spool valve apart, could there be some bad "o" rings inside that's allowing the oil to bypass. Is there any adjustments that could be made?

[ohiowoodchuck]

I would lean toward a broken or weak spring, if there made like the ones I have rebuilt in the past.

[beenthere]

pabar
Likely the spool itself doesn't have "O" rings, but instead is machined to fit. Something causing an apparent leak past a machined section that may have been caused by some dirt in the hyd. oil.
Or something not letting the spool return to "home" position.

You can look at the different SCV valves by going to jdparts.com. Shows three different valves for different models and serial numbers. Would need to match them up, but can see the breakdown of internal valve parts.

[rowtohoe]

I have a 540A and my blade was doing the same thing. I disconnected one blade cylinder at a time to see if it was the cylinder. It was. I rebuilt one cylinder and it stopped. I do not know the workings. But it stopped my blade from creeping.

[Maine logger88]

The blade on my 540b will creep up aswell but if you put down pressure on it it stays down. Idk I never looked into it lol

[redprospector]

I replaced the blade valve on my 440b a few years ago. I couldn't get parts through John Deere, and finally found an outfit that offered an "upgraded" replacement, which was just a spring centered valve with a float position. The original JD valve was way too complicated for what it does (like a lot of their stuff).
Good luck, and get that thing fixed. I want the blade down hard when I'm on the ground.

[pabarhunter]

Thanks for all the great information. I never owned a skidder before, worked for a friend of mine throughout high school running his. I will take each suggestion and use them to start eliminating possibilities. Everyone have a safe and merry Christmas. jimmy