JD 630 power steering problem

[Wranglerdude]

Discovered that my 630 turns to the right if I take my hand off wheel. Steering works fine both directions, just takes off to the right when you don't have a hand on the wheel. Never noticed it until a prospective buyer drove it today on a gravel laneway. I don't know if it's just because of the cold weather or what. My local JD guru has passed away. Any ideas how to adjust for this problem? Thanks.

 

[cushman]

That problem is easy to adjust,but you need a manual to know how to do it,or someone close enough to do it for you.Even an I&T manual will
get you through that procedure if you have a mechanical aptitude.It involves removing the nose piece and slightly loosening the valve
retaining bolts,then taping the valve forward or backward until it is centered,then retightening the bolts.

 

[coonie minnie]

Cushman is dead on. The valve needs to be centered, and like he said, get the manual to do it. It will help a lot. If it was a cold day that will make the problem seem worse til the oil
warms up.

 

[Gene Davis (Ga.)]

From hard learned experience. Don't have your hand on the steering wheel as you crank it up when it needs
centering!

 

[Wranglerdude]

I do have a little skinny IT manual. Found the part that talks about moving the valve to make steering effort equal but it didn't say anything about correcting the wheel turning on its own. The tractor was cold to start with today and that may have made it worse. I've had this tractor for 18 years and never noticed any problem but I never take both hands off the wheel either. Thanks for all the help everyone. I had part of that valve assembly off a few years ago while putting in a new radiator. Maybe that's when something got moved.

 

[matthies]

And it doesn't move much to correct itself. Maybe scribe a line on the valve to the housing, might just move the width of the line you scribe to fix.

 

[fixerupper]

You probably know this, but scribe a mark across the valve and worm gear housing as a reference point, then just barely tap the housing to adjust it while watching the reference point. A few thousandths makes a difference. Could be the roll pin inside has a flat spot worn on it too and a worn pin can make centering perfectly hard to do. I've been in there and replaced the pin but it's been awhile. Maybe someone on the John Deere board can walk you through it if you can't get the valve to center the way you want it to be.

 

[Wranglerdude]

I re-read the IT manual no. JD 16 this am and found where it talks about the tractor drifting one way or the other. Looks like moving that valve body just a little will fix the problem. I may have had that off when I replaced the radiator almost 10 years ago. It wouldn't surprise me if the problem went away once everything is warmed up because I've never noticed the problem in field use. Thanks again for all the help.