John Deere 3140 Steering Issue

[bigblock76]

Long story short, When driving the tractor, I constantly have to keep turning the steering wheel to the right (slowly) to keep the tractor straight. If I turn the wheel all the way to the right or left to dead lock it, it locks, when the steering cyl is all the way extended or retracted, but you can still slowly turn the wheel after it locks.

This tractor is 2wd and has 1 steering cylinder up front. It has the oribtal steering unit. Its an open station tractor.

I have rebuild the hydraulic cylinder about 4 years ago when I attempted to fix this issue. The cylinder stopped leaking externally, but the steering issue remained the same.

Last summer I rebuild the orbital. All seals including the 2 really small seals that didn't come in the kit originally. After assembly and a test drive, it still responds the exact same way.

The power steering hydraulic filter (separate can on the side of the transmission case) has been also changed.

It's one of those things that is super annoying that your arm hurts from turning the wheel all day long the same way to stay straight. But also one of those things I only have so much time to dedicate to as the tractor runs nicely for the most part. Since this has been years in the making to resolve, I'd like to give it one more shot at it.

Does anyone have any ideas how to isolate this issue? Or to try something else to repair?

 

[beenthere]

Normal, in my opinion.
Power steering is not like an auto.. no direct mechanical connection. Just hydraulics.

Unless I misunderstand your explanation.

 

[Tx Jim]

What's your tractor's serial number? It appears from viewing 3140 PC JD offered a PS conversion kit.

 

[MORRISONSTEEL]

If i understand it correctly the conversion kit was to eliminate the adapter plate (ex al38398) to steering valve stack and attaching screws and made it a direct connection. I think it was related to sealing issues between steering valve and plate, the holes where large enough on the plate that if not careful it shifted and leaked as well as some issues to pulling out the threads. So the kit was used in some cases to eliminate that issue.

 

[bigblock76]

Normal, in my opinion.
Power steering is not like an auto.. no direct mechanical connection. Just hydraulics.

Unless I misunderstand your explanation.

Let me try to explain, if I drive the tractor straight, I likely need to slowly turn the steering wheel to the right about 6 times around over 800 feet.

 

[bigblock76]

Tractor is early, around 80000 somewhere there if I remember off hand.

 

[bigblock76]

Is there a way to diagnose this correctly. Flow chart to diagnose?

 

[Tx Jim]

This is WAG on frt tire toe in possibly being at fault but it wouldn't take much time to check. Has toe in been checked lately?

 

[bigblock76]

This is WAG on frt tire toe in possibly being at fault but it wouldn't take much time to check. Has toe in been checked lately?

They have always looked pretty square to me, but I can do some rough measurements to verify.

 

[DLTTrekkers]

To test....remove pipes from silinder and block is off ...start and turn steering lightly to one side and see if steeringwheel keeps on turning slowly...try that to the other side as well. A very slow turn will be normal. To test steeringsilinder turn wheels to end of stroke... block only one side and see if oil exits the silinder ?