Dk40 hst creeping backwards

[Illini22]

Last time I was at my property I noticed that my dk40 was creeping backwards. It had never done this before. I have put 3 hours on it since the 50 hour fluids change. I topped off the hydro fluid because it was barely on the dip stick. It's still very hard to see (clear). Would an over filled hydraulic system cause the trans to creep? I checked the linkage for obstructions, sticks, etc. Worked the pedals etc.

 

[George2615]

The linkage might need to be adjusted. Maybe there should be a little free play between fwd and rev.
Does the linkage shaft have grease fittings or can it be lubed.

 

[k0ua]

This issue is addressed by the neutral valve. I am suggesting you take it to the dealer or get the service manual.

here is some dialog from the manual.

0°, the rotating speed of the output shaft in the hydraulic
motor should be 0 since there is no oil supply. However,
it is almost impossible for the driver to adjust the HST
swash plate to 0°. If the angle of the swash plate is out
of 0°, the tractor starts to move and keeping the neutral
position is very difficult. To solve this problem, the neutral
valve is installed to secure the neutral range.

The neutral valve (1) drains the oil in the circuit through
its orifice so that the hydraulic motor does not rotate
when the amount of oil supplied to the motor is insufficient
even though the angle of the swash plate in the
pump is close to 0° (not exactly 0°).

As the swash plate angle is increased, the pressure of
the oil supplied by the pump increases. This pressure
increases to the point that the pressure is greater than
that of the return spring pressure of the neutral valve.
The neutral valve moves to close the orifice.



There are adjustments on the Hydrostat pedal shaft linkage. And that could be the problem That is listed as a possible problem along with the neutral valve, it could be either. .. There are several diagrams. with measurements to adjusting and tension nut and shaft length.. You really need to study the manual if you are going to tackle this. Otherwise, load it up and take it to the dealer.

 

[k0ua]

What they are trying to say, in the above dialog is that is is impossible to exactly hit 0 degrees of angle on the swash plate, and if there was not a mechanism to make a "dead spot" in the swash plate angle the tractor would always drift either forward or backward. BUT they included a mechanism to drain away small pressures so that the hydro motor would not turn when the swash plate angle was just near 0 degee's. It could be faulty, or it could just be the adjustment of the pedal linkage I referenced above.

 

[Illini22]

Thank you for the description. I didn't see any grease fitting put I did spray down all the linkage before putting it away. If it is the neutral valve, I wonder how it got out of adjustment.

 

[TJP89]

The problem is almost certainly the pedal linkage. Somewhere down there there should be a rod or nut that adjust the HST pedals, can't help you find it, as I have the very differently setup CK, but when you do, adjust it so the tractor doesn't move in in gear with no pressure on the pedals. Your manual should help you here.

 

[SwingOak]

I had the same problem after the dealer changed the transmission fluid in my DK50 SE HST. They came out to the farm and adjusted it after I got it back, but it started doing it again. I found the problem - the "ears" on the pedal shaft that connect to the linkage were bent. I removed the pedal assemblies, straightened them out, and gave them a coat of paint to keep them from rusting. The factory powder coat did not have the best coverage on top of the linkage assemblies. I'll post some pictures later.

It's still creeping backwards but I think that's because they adjusted the neutral without realizing the parts were bent. It's soft, mild steel and not that thick. I think what happened is with the very cold temperatures we had recently, there was a lot of resistance to linkage movement, causing the damage.

It's sort of a wimpy design for an otherwise robust tractor.

 

[SwingOak]

OK here are some photos.

You can see in these that the "ears" on the pedal shafts that connect to the linkage are twisted, and the powder coat has cracked off:

Here you can see how the ears twisted, and the bad powder coat on the top side of the levers:

Here they are straightened out before painting. They still look a little bent but that's just from the angle of the camera:

And here is a view of the neutral position adjustment. Apparently the service tech who came out to my farm did not have a 10mm wrench with him because he used vice grips on the coupler nut. It's a lot easier to access the neutral adjustment when the hydraulic lines for the loader are disconnected. I found the couplings have to be lined up perfectly or they won't go together. If the loader was being put on & taken off more frequently I would definitely replace them. It worked fine after putting everything back together and adjusting the neutral position. So I'd suggest to my fellow Kioti HST owners to go easy on the pedals when it's cold out and the tractor is cold.

 

[Coyote machine]

Great pics of the mangling of the ears! Wow, your dealer's guys did that!:confused2:
What did you use to get the ears straight? Heat? Brute force? Is everything working right now?
How much time from start to finish on the unmangling?

 

[southerniltractor]

Nothing annoys me more than taking a tractor (car, truck motorcycle) to a "professional" service department and seeing crap like that! Exactly the reason I do EVERYTHING myself (outside of warranty work) and try to select only the best and recommended service departments. Not having a 10 mm wrench? What the heck? I'm not a mechanic, and I bet I've got 5 (in different orientations) in my tool chest.

Okay, rant over. Thank you for providing the pictures and how you resolved your problem. I'll go easy on the pedals this winter.