CK4010 SE Hydro transmission hiss and stall

[audiocontr]

2018 Ck4010SE with 350 hours on it.

Lift capacity is working normal, but I'm having an issue with the transmission. It's hissing and stalling when presented with resistance.

The transmission just started hissing while pulling a heavy trailer. Any resistance, and the tires stop spinning and the tone of the hydro changes. Almost sounds like it's bypassing. The wheels do not spin, and it eventually stalls out.

It's the same in L or M. It begins to make the same sound on take off while in high, but moves.

Fluid is full. Tractor moves fine on its own. I used it all winter without any issues. Brake isnt on =) it rolls just fine in neutral. I will swap out fluids/filters this weekend.


Any thoughts?

 

[Robin Veerman]

Don’t swap fluid and filters too fast…unless it’s due or overdue. However doing an oil sample would be a great idea!! Talk to your tractor dealer or a heavy truck shop. Change fluids and you wouldn’t be able to investigate the oil that’s currently being used for wear metal, contaminants etc…
Tell us a little bit more. How heavy is the trailer, give us your best guess, or show us a picture.
How long have you owned the tractor? An HST transmission is different from a gear transmission and is operated differently. RPMs above 2000? Just saying…

 

[audiocontr]

Appreciate it Robin,
Ive owned the tractor for 3 years. Put 250 hours on it. I have a Kubota HST ive driven for a decade. I tend to use the function that increases rpm with press of the peddle, but found no difference with it engaged, or simply raising the rpms to 2k+. It does happen quicker when in 4wd, but that would make sense given the increase in resistance.

The trailer is a 6'x10' single axle filled with fire wood. Maybe 2500 - 3000lbs total? Nothing i havent moved with it a dozen times a season with any one of my tractors. This time the kioti hissed, making me think i was up against a log or something. Nope, standard flat pull, and no obstacles.

I put my box blade on it yesterday and could barely pull off the dirt mound ive pulled from for years. normally i'd break traction in the mud if it were caught on a root or stone. now it feels like a slipping clutch.

Whats interesting is the sound of the transmission. All is fine until it tries to apply torque, and then i hear what sounds like a bypass maybe? a higher pitched sound of the transmission. Once i release the peddle, sound goes back to normal. i can get a little torque, or move the tractor on its own fine... but once it hits a bit of drag, the sound changes and no power at all.

I will make sure i pull an oil sample if i do attempt a fluid swap.

 

[Robin Veerman]

Ok, just checking to see the history of the tractor. You are obviously quite familiar with it.
If it has rear remote(s) is the lever in the neutral position?
Yes, save a sample of oil if you do change it. Hopefully someone else with your exact tractor will chime in. Keep us posted...