DK40 front bearing failure @ 1300 hours

[PA hayseed]

Just to clarify, I have moved at least 200+ tons of gravel, as I will get a triaxle delivery of 23 tons at a time. I have moved a pile of sandstone that I estimate to be around 60 tons several times, as I cut it and use it then move it to the next location. I could not even fathom a guess as to how much dirt and topsoil ( a couple hundred tons). I used the FEL for excavation of my house when I moved it, and I used it for filling in the old house area (think angled front end loader use). I used it for excavating my mothers property, my buddies property, and two driveways (including shale compaction). I cleared out an old farmstead with it. and to top it off Every year the state "gifts" me anywhere from 1-4 tons of antiskid spread across my road frontage, by the end of winter. I don't have a cluse as to how much snow/ice the thing has moved. I also use it to move/ sift my topsoil/compost pile yearly. My point is that I have used mine a lot and that may not be indicative of the standard tractor users usage.

 

[liberty2701]

Just to clarify, I have moved at least 200+ tons of gravel, as I will get a triaxle delivery of 23 tons at a time. I have moved a pile of sandstone that I estimate to be around 60 tons several times, as I cut it and use it then move it to the next location. I could not even fathom a guess as to how much dirt and topsoil ( a couple hundred tons). I used the FEL for excavation of my house when I moved it, and I used it for filling in the old house area (think angled front end loader use). I used it for excavating my mothers property, my buddies property, and two driveways (including shale compaction). I cleared out an old farmstead with it. and to top it off Every year the state "gifts" me anywhere from 1-4 tons of antiskid spread across my road frontage, by the end of winter. I don't have a cluse as to how much snow/ice the thing has moved. I also use it to move/ sift my topsoil/compost pile yearly. My point is that I have used mine a lot and that may not be indicative of the standard tractor users usage.

Wow, you worked it. I do all my own repairs. I will monitor and maybe do a bearing/ seal replacement at 1000 hrs as a precaution.

 

[fatboycowen]

What about pulling on the front wheels to check for play every time you run the machine? Like you would on a race car.

 

[dfkrug]

I don't know how much that box blade wieghs probably 500-600.

You guys with the DK 40/45/50 tractors: your FEL has enormous lifting capacity. And not just compared
to my relatively wimpy CK30 loader. For serious FEL work, I can see why you need 1000# on the hitch. What
I would do if I did not have a backhoe attachment is to rig up your box blade with some brackets or a receiver to hold
more weight. A custom weight would work, but you could also use an old engine block (or 2).

 

[JimR]

You guys with the DK 40/45/50 tractors: your FEL has enormous lifting capacity. And not just compared
to my relatively wimpy CK30 loader. For serious FEL work, I can see why you need 1000# on the hitch. What
I would do if I did not have a backhoe attachment is to rig up your box blade with some brackets or a receiver to hold
more weight. A custom weight would work, but you could also use an old engine block (or 2).

The custom heavy weight box in the rear would be the solution for this counter-balance problem for tight space usage.

 

[Billrog]

A counter balance just behind the back wheels will help keep the back wheels on the ground with a bucket full but as far as a fulcrum goes to keep weight off the front wheels is almost insignificant considering how far the loaded bucket is out in front the back wheels.

 

[DieselBound]

A counter balance just behind the back wheels will help keep the back wheels on the ground with a bucket full but as far as a fulcrum goes to keep weight off the front wheels is almost insignificant considering how far the loaded bucket is out in front the back wheels.

Yup!

Anyone who is around weigh scales might be able to prove this all out. IF there's any advantage is is only a small amount.

The nature of things is that running them at near max capacity is going to offer up a shorter lifespan. It's the trade-off of getting more work done faster.

 

[dfkrug]

A counter balance just behind the back wheels will help keep the back wheels on the ground with a bucket full but as far as a fulcrum goes to keep weight off the front wheels is almost insignificant considering how far the loaded bucket is out in front the back wheels.

The downward force exerted on the 3pt hitch results in upward force on the front of the tractor as we all
know. That amount is reduced by the length of the moment arm, but it is hardly insignificant. Draw a
free-body diagram. For example, if you centered a point-load of 1200# on your hitch at, say, 3-feet
behind your rear axle, that will result in a 400# upward force about the rear axle at
9 feet in front of the rear axle. Of course, this is a rough approximation; loads are
distributed, not point loads.

The DK40/45/50 also has an enormous 3-pt lifting capacity, maybe 3000#? I would
probably shoot for 1500# on the hitch at 4 feet behind.

 

[JimR]

The downward force exerted on the 3pt hitch results in upward force on the front of the tractor as we all
know. That amount is reduced by the length of the moment arm, but it is hardly insignificant. Draw a
free-body diagram. For example, if you centered a point-load of 1200# on your hitch at, say, 3-feet
behind your rear axle, that will result in a 400# upward force about the rear axle at
9 feet in front of the rear axle. Of course, this is a rough approximation; loads are
distributed, not point loads.

The DK40/45/50 also has an enormous 3-pt lifting capacity, maybe 3000#? I would
probably shoot for 1500# on the hitch at 4 feet behind.

If that is the case maybe 2K would be even better.

 

[oercheron]

I see that this is an older thread but since the same thing happened to my DK45SE at around 1000 hrs I thought it may help someone else for me to comment.

The left front bearing failed catastrophically, taking out the axle shaft and cover. Cost was about $1000 CAD for all the parts, I did the labour myself.

After repairing the left side, I took the right side apart. Bearings were horribly scored and looked to me near failure. I replaced them, an easy job, cost about $75 and both bearings were standard automotive type, available anywhere.

My use of this tractor is almost always as a loader, and I usually carry a bucket full of heavy material (gravel, boulders, concrete blocks) a long distance over rough ground. In addition I have added a spill guard to the top of the bucket and a cutting edge to the bottom, increasing its capacity. I do have about 850 lbs counterweight.

I will from now on be replacing front wheel bearings at around very 500 hrs, as they are not all that expensive, and it is not a big job to change them.

 

[Kioti Paul]

oercheron, thanks for the post! I too have a DK45, with 1000 hrs. My tractor is used for haying, so I never considered the loader to be carrying a lot of weight, however I do carry 700/800 lbs all around my hay field quite a bit (10 square bales + the grapple..it does add up).

Before the spring cutting, I will inspect the bearings; and report back my findings.

Thanks for the heads up!

 

[oercheron]

oercheron, thanks for the post! I too have a DK45, with 1000 hrs. My tractor is used for haying, so I never considered the loader to be carrying a lot of weight, however I do carry 700/800 lbs all around my hay field quite a bit (10 square bales + the grapple..it does add up).

Before the spring cutting, I will inspect the bearings; and report back my findings.

Thanks for the heads up!

Sounds like with your use you might be OK, but it will be interesting to see what your bearings look like. I usually have 1500 - 2000 lbs in the bucket, and traveling over rocky, rough ground. That is pretty much all I do with this tractor.

The front axle oil needs to be changed every 400 hrs, that would be a good time to check as you lose all the oil when you take it apart anyway.

 

[liberty2701]

Do you happen to have the bearing numbers available? Is the gear oil responsible for lubing these bearings? Would a higher quality synthetic or more frequent oil change extend the life of these bearings?

 

[oercheron]

Do you happen to have the bearing numbers available? Is the gear oil responsible for lubing these bearings? Would a higher quality synthetic or more frequent oil change extend the life of these bearings?

Bearing numbers are 6208 and 6209.

Gear oil does lube these bearings, and I was using synthetic gear lube. Maybe more frequent changing would help, but mostly I think the problem is caused by the stress I put the axle under. Front tires buried in mud and rocks nearly to the top, down in some hole that needs full power to pull out of, and a full bucket. Day after day. I am really surprised that the machine stood this abuse so well for 1000 hours. But those are the job requirements, and extra repairs are factored in to my prices.

 

[liberty2701]

Bearing numbers are 6208 and 6209.

Gear oil does lube these bearings, and I was using synthetic gear lube. Maybe more frequent changing would help, but mostly I think the problem is caused by the stress I put the axle under. Front tires buried in mud and rocks nearly to the top, down in some hole that needs full power to pull out of, and a full bucket. Day after day. I am really surprised that the machine stood this abuse so well for 1000 hours. But those are the job requirements, and extra repairs are factored in to my prices.

Great. Thank you

I wonder who Kioti uses for the OE bearings? Maybe there is a better brand out there?

 

[oercheron]

Great. Thank you

I wonder who Kioti uses for the OE bearings? Maybe there is a better brand out there?

The Kioti dealer supplied the bearings for the left side. He said that he just gets them from a local automotive supplier. The right side I did 2 weeks later and bought them from a local bearing house as that was closer. The kioti dealer charged me just a couple of dollars less than the bearing house. Very fair I thought.
All the bearings were name brand, Timken or such.

 

[xcgreene]

I see that this is an older thread but since the same thing happened to my DK45SE at around 1000 hrs I thought it may help someone else for me to comment.

The left front bearing failed catastrophically, taking out the axle shaft and cover. Cost was about $1000 CAD for all the parts, I did the labour myself.

After repairing the left side, I took the right side apart. Bearings were horribly scored and looked to me near failure. I replaced them, an easy job, cost about $75 and both bearings were standard automotive type, available anywhere.

My use of this tractor is almost always as a loader, and I usually carry a bucket full of heavy material (gravel, boulders, concrete blocks) a long distance over rough ground. In addition I have added a spill guard to the top of the bucket and a cutting edge to the bottom, increasing its capacity. I do have about 850 lbs counterweight.

I will from now on be replacing front wheel bearings at around very 500 hrs, as they are not all that expensive, and it is not a big job to change them.

Thanks for the information. I plan on opening mine soon here at 500hrs for inspection and reporting back. I would call my loader use average. With every bit of useful info we can get on this thread we can come up with an hour count where we all should start thinking about changing the bearings in maintenance, depending on usage.

Did you keep up with greasing the upper bevel gear bearing?

It does continue to sound like these bearing failures are coming from heavy loader use. No problem there, its just good to know what and when to expect.

 

[JimR]

Too bad these bearings are not roller style instead of ball type. Roller bearings will take a lot more load than a ball style bearing.

 

[oercheron]

Did you keep up with greasing the upper bevel gear bearing?

Yes I keep up with maintenance according to the schedule in the manual.

You can see some of how the tractor gets used on my YouTube channel at muleskinnerjack
- YouTube

The video titled "Making gravel for the trail" shows the DK45SE being used.

 

[xcgreene]

Too bad these bearings are not roller style instead of ball type. Roller bearings will take a lot more load than a ball style bearing.

Be forewarned, the following has not been tested in this specific application in any way. Just "thinking out loud"

After reading through SKF's bearing book, I would say that their NUP208ECP and NUP209ECP roller bearings could possibly be a suitable replacement for the 6208 and 6209 ball bearings. Beyond just their correct sizing, these rollers have a dynamic load carrying capability double that of the 6208 and 6209.

18kn to 62kn and 35 to 70kn respectively.

I believe NUP would be best due to its availability and inner outer race retention specifically designed to locate a shaft axially in both directions. ECP should allow for oil bathing. However, there is a certain amount of axial play these single row rollers would have due to their nature that a double taper roller would handle better, but they are out of the game due to size requirements. Even still, SKF shows an axial tolerance of 0.05 to 0.15mm, so very little.

All things considered, I think these rollers would be worth testing should someone find themselves curious enough and willing to take a risk.