Mowing Kioti DK55 TRANS WAS BOILING HOT after bush hogging WHAT HAVE I DONE???

[quadmaster50]

Got a 2007 Kioti DK55 Gear trans, just turned 600 hours. Wile bush hogging high weeds with a 8' rotary for 5 hours i started noticing a smoky smell. Water temp gauge was ok, decided to clean radiator screen and keep going. Towards the end of the evening as the sun was going down i started seeing smoke. I got off to make sure i didn't have a fire. I walk around to the back of the rear end / pTo area and i spit on the axle housing, BOILING HOT! i shut tractor off to inspect the situation and try to figure out what the **** i have done... NO, brakes were on, they don't drag, The remotes were not activated and were " open ". I was running 2300-2400 rpm, slight hills, in MED range going between 3rd and 4th.. ( 2-3 mph)
I let her sit for 5 min and limp it back to the truck, i checked the rear end / hydro oil and it was a touch low, less than a qt id guess. I dump a quart in from my truck ( always carry extra oil and fluids) and as I'm pouring it in the rear axle housing fill i can hear the stuff boiling as its going in..... I mean it was F'IN HOT!!

What have i done to my tractor? Will over working the PTO cause this? it was working pretty hard. Id say 75% of its rated power was being used constantly, but my god, its a tractor right...?????

 

[jabelding]

Something is not right with your tractor blowing relief all the time or something dragging severely in the transmission. Tractors are designed to have enough fluid in the transmission reservoir to cool it before it circulates back to the pump shouldn't be much over 160 deg under normal and severe operating conditions. Should never be that hot where water boils on the outside!

 

[quadmaster50]

Something is not right with your tractor blowing relief all the time or something dragging severely in the transmission. Tractors are designed to have enough fluid in the transmission reservoir to cool it before it circulates back to the pump shouldn't be much over 160 deg under normal and severe operating conditions. Should never be that hot where water boils on the outside!

I simply dont know, I'm changing the fluid in the morning and going to give it another try i suppose. Im trying to mow 50 acres, only got 11 done so far,,

 

[MinnesotaEric]

Got a 2007 Kioti DK55 Gear trans, just turned 600 hours. Wile bush hogging high weeds with a 8' rotary for 5 hours i started noticing a smoky smell. Water temp gauge was ok, decided to clean radiator screen and keep going. Towards the end of the evening as the sun was going down i started seeing smoke. I got off to make sure i didn't have a fire. I walk around to the back of the rear end / pTo area and i spit on the axle housing, BOILING HOT! i shut tractor off to inspect the situation and try to figure out what the **** i have done... NO, brakes were on, they don't drag, The remotes were not activated and were " open ". I was running 2300-2400 rpm, slight hills, in MED range going between 3rd and 4th.. ( 2-3 mph)
I let her sit for 5 min and limp it back to the truck, i checked the rear end / hydro oil and it was a touch low, less than a qt id guess. I dump a quart in from my truck ( always carry extra oil and fluids) and as I'm pouring it in the rear axle housing fill i can hear the stuff boiling as its going in..... I mean it was F'IN HOT!!

What have i done to my tractor? Will over working the PTO cause this? it was working pretty hard. Id say 75% of its rated power was being used constantly, but my god, its a tractor right...?????

Your thermostat in the oil cooler is shelling or your oil cooler radiator is plugged up with junk.

 

[quadmaster50]

Your thermostat in the oil cooler is shelling or your oil cooler radiator is plugged up with junk.

The only oil cooler is for the motor, its a sandwich cooler at the oil filter. It don't have any coolers for the trans at the radiator as its a manual transmission. ( yet )

 

[MinnesotaEric]

Well, I went out and serviced my tractor, kicked the bush hog on and the **** PTO clutch is slipping horribly! It wasn't doing this friday when i shut it off.... I could burn this POS.. I googled it and it seems many people have been having super high fluid temps ( 260+ deg) with the DK55 when worked hard.... Ive put 600 hours on this tractor and know how to operate it. It never done this before until i put the larger mower on it.

Okay, time to add a thermostatically controlled oil cooler. If there is a service manual floating around there should be two port for tapping into to hook up an oil cooler.

PTO clutch is electric isn't it?

 

[ritcheyvs]

I am more of a Diesel engine guy (vs transmission) but this is a gear transmission so I'll comment.

This is NOT normal. Continued operation in this state may (eventually will) damage something.

There may be something wrong with the hydraulics, either at the loader, at the remotes, or at the 3-point (unless you have added valves, like a third function). Operate the loader and remote levers to verify the hydraulics load on the engine when they should (like brief deadheading) and that the engine unloads (by ear) when you remove each hydraulic load.

Another possibility is a slipping PTO clutch. You might experiment to see if the overheat is associated with PTO operation.

Be sure you use a "premium" tractor fluid that is specifically rated for wet brakes (and clutches). I think the wrong kind of hydraulic fluid might cause the PTO clutch to slip.

 

[ovrszd]

I think your PTO clutch is the culprit. Adding a cooler might lower the temps of the oil, but won't fix that....

I'd call my dealer and talk to a mechanic, not the service tech. See if there's any adjustment for this clutch? See if it's a normal problem? What's the solution?

I'm afraid you have fried your PTO clutch. Gather all the information you can before you let a shop work on it.

Sorry for your problems. Burning the tractor is not the solution.

 

[quadmaster50]

Well, i took it into the local dealer and they said that these are know for hot trans problems, they are putting new seals in the PTO.. they say that can work one second and not the next time you turn it on... Very poor design according to them, and its in the middle of the tractor!

 

[ovrszd]

So, when you go back to brushcutting again what do you expect?

 

[quadmaster50]

So, when you go back to brushcutting again what do you expect?

After reading all the other people having boiling transmission issues with the DK55, when its fixed i'm trading it in to the deere or Kubota dealer. I am done with the Kioti's for good. I love the little motor and seems well built but there is issues with the series..

 

[ovrszd]

I'd probly feel the same.

 

[holeycow]

Issues with the series??

My DK90 can bale running close to max pto power for 10-12 hours straight without getting more than nicely warmed up, as machines go.

 

[holeycow]

Huh? I found one other hot little dk in a search...but not "all the other people"...

 

[ritcheyvs]

Well, i took it into the local dealer and they said that these are know for hot trans problems, they are putting new seals in the PTO.. they say that can work one second and not the next time you turn it on... Very poor design according to them, and its in the middle of the tractor!

I am skeptical. I found little online about hot transmissions on DK gear models. Is your comment about "known for hot trans problems" based on data from real owners or just that dealer's comments?

What kind of PTO seals is the dealer installing? Did you buy this tractor used and did you buy it from this same dealer? The PTO clutch pack could be contaminated from the wrong type hydraulic oil by previous owner. Might you be overloading the clutch with the high grass, causing it to slip; what if you mow slower?

What tests or inspections did the dealer do? Did he measure the hydraulic pressure at the clutch pack servo? Did he test for internal leaks at the PTO clutch piston and shaft seals? Did he test the clutch slip torque with the clutch engaged? Maybe you just didn't include (or have) details but it sounds like that dealer "blew you off."

I have had a 2006 DK45s gear model for seven years that I use with a six ft rotary cutter and finish mower. I read almost all Kioti owner/operator posts here on TBN and this is the first I've heard of hot transmissions.

 

[DieselBound]

I'm with ritcheyvs on this.

I'm the kind of guy that if something fails on me I HAVE to know why. I want to rule out anything that I may have done: yes, I know, it's rare that operator errors occur (I make this last point because I recently had an expensive chainsaw puke on me- I'm spending money shipping it off to a guru so I know for certain what happened (it stores a bunch of info- local yokals are worthless, didn't even know you could read data from the saw! - yes, one cannot really do this with a tractor, but, I wouldn't be inclined to trust the dealers assessment here (which might be the better reason to switch to someone else?).

Dealer sounds like they're just trying to cover their butts. They don't know what happened, but they do see that seals were damaged. As others have stated, the PTO clutch seems suspect (it's what was causing excessive heat; the seals were the victims of it).

600 hours and it does it now. SOMETHING happened out of the norm.

How many hours have you put on this tractor?

Have you ever had to add fluid before?

Does 3rd and 4th gears really give only 2 to 3 mph? I run HSTs, so I really don't know.

8' cutter is on the larger side. How tall was the grass? What kind of grass?

What were your ambient temps?

 

[rd_macgregor]

"Does 3rd and 4th gears really give only 2 to 3 mph? I run HSTs, so I really don't know."

I'm pretty sure he said he was operating in mid range, so that speed sounds about right (well, based on my DK45 experience, anyway).

I'll be following this thread since, though I haven't had an overheating issue, I have experienced PTO clutch slipping a couple of times when a large branch jammed my Wallenstein BX62 chipper. I expected to have the shear bolt go or the tractor die, but it kept ticking over with the PTO engaged but stationary! Repair of an issue like that sounds expensive.

 

[ovrszd]

"Does 3rd and 4th gears really give only 2 to 3 mph? I run HSTs, so I really don't know."

I'm pretty sure he said he was operating in mid range, so that speed sounds about right (well, based on my DK45 experience, anyway).

I'll be following this thread since, though I haven't had an overheating issue, I have experienced PTO clutch slipping a couple of times when a large branch jammed my Wallenstein BX62 chipper. I expected to have the shear bolt go or the tractor die, but it kept ticking over with the PTO engaged but stationary! Repair of an issue like that sounds expensive.

Bummer. That is not a good thing...... Not bashing Kioti in any manner,,,,, but that's not good!!!! Should kill the tractor.

 

[quadmaster50]

I can tell there is some butt hurt with saying the DK55's have a issue with a hot trans.. Its not a opinion when it happens to a few DK55 doing the same thing with the exact same outcome... that is called a problem, like it or not! If all you can find is a "few cases" of the same tractor, doing the same thing, what more proof do you want?? -Thats all I'm going to get into that, I am not looking to argue.

I talked to several Kioti dealers and even talked to a engineering rep for the company, A few of the dealers have seen this before, it was usually thought it was caused by slipping PTO clutches causing the heat, its not. The Kioti guy said that because the PTO is operated via hydro pressure, when its on it is constantly bypassing fluid in its self creating heat, add the extreme pressure of running the 540 at near max output on the bat wing, the trans and rear end gears pulling a 3000LB mower plus the tractor and loader over a few hours its going to build up excessive heat. They said basically the system uses the cast iron to get rid of the heat, when it is overwhelmed and it will got hotter and hotter and it has no way of warning the operator. The DK55 open station has no cooler for the system at a all, the cab version did because of the extra weight it had to carry to try and keep it cool and prevent this from happening. They said its simply a case of a over worked system, the tractor is designed with 60% duty rating on 12 hour cycle not 90 or 100% as I was asking of it, although it happened within 2 hours or so.

What was the failure?

The piston seals in the clutch pack were ruined, it got to hot and blew them out. It was bypassing its own fluid and notable to lock down on disks. The clutch pack looks like new and will just need new seals and a system flush. It has a axle seal and a PTO seal leaking also because of the heat. None of the parts were expensive but they are charging almost 2200.00 to split it and fix it plus 370 in parts and fluids.

Keep in mind, this doesn't/won't happen with running a little 6' mower or tiller, you have to work it hard, near its max output for a few hours at a time. I guarantee you, if you work it hard it will BOIL!!! No ifs, ands or butts about it!

I bought a john deere 5400 MFWD yesterday to finish what the Kioti started, I ran it for 9 hours straight today, pulling a 15" mower at 6MPH and its trans was not even hardly warm.... Keeping it green from now on!

 

[CalG]

Well, You went from a 5500# 55HP tractor to a 7000# 70HP tractor.

Seems like you fit the tool to the job! Good going.
The change likely had little to do with the paint color