NX4510 Three-point Jumping Back to Set Height

justman777 · Jul 22, 2019

All,

I've got what may be an issue with my three point and would appreciate some input to see if this is abnormal behaviour.

My three point will intermittently "jump" back to the set height. I usually notice it while the tractor is at idle, but I believe it's happening while I'm working too. Just can't tell while I'm working because I'm driving over ruts, gopher hills, etc. Happens about every 10-15 minutes. I can usually tell when it's going to jump because the engine bogs down just a smidge, the trans makes an odd gurgling noise, and then the three point will jump back to the set height. This was happening about every 3 minutes, but I changed out the MLS valve under warranty and it went to a the current 10-15 minute time frame between jumps. It only tends to happen when I have my ballast barrel (1200 lbs) or my shredder connected....both heavier implements. Makes me think the heavier weight is causing fluid to bypass somewhere.

Anyone else experience this? Normal behavior?

BTW, my three point and loader will also leak down slowly overnight.

Appreciate any input!

Thanks!

Amvcane · Jul 22, 2019

justman777 said:
Makes me think the heavier weight is causing fluid to bypass somewhere.
!

I spoke to my dealer about the different types of 3 pt jumping and bouncing. He had said the position control 3pt is feed back controlled using some linkages comparing position of lever and position of 3pt. The position of the lever tells the 3pt what height it should be, for example height 7. If the valve leaks and the 3pt drops without moving the lever the feedback linkage tells the 3pt ( hey the lever says the 3pt should be at 7 and jumps it back up to height 7. If the leak is bad the 3pt will bounce continuously essentially caught in a feed back loop.

justman777 · Jul 22, 2019

Amvcane said:
I spoke to my dealer about the different types of 3 pt jumping and bouncing. He had said the position control 3pt is feed back controlled using some linkages comparing position of lever and position of 3pt. The position of the lever tells the 3pt what height it should be, for example height 7. If the valve leaks and the 3pt drops without moving the lever the feedback linkage tells the 3pt ( hey the lever says the 3pt should be at 7 and jumps it back up to height 7. If the leak is bad the 3pt will bounce continuously essentially caught in a feed back loop.

Well, that's interesting. I was wondering what tripped the whole "jump back to set height" scenario.

Did your dealer mention if this was an MLS valve issue? Something else?

Thanks!

Amvcane · Jul 22, 2019

He did mention dirt or debris in the valve blocking an orifice will cause the symptoms.
We were discussing this on my CK35. Not sure how the newer or larger tractors function.