L3540 front axle case and hub bearings

[Tony H]

Just writing about a friends experience with his 2009ish L3540. 1900 hours.
It has the LA724 FEL... He has had issues with front axle bearing disintergrating. He is way up on maintenance, he uses all Kubota fluids yet he has had 3 failures with front axle bearings falling apart. Twice, a little fluid leak had us pulling the front axles of only to find balls in the bearing missing and scored up axles. The third time, the tire dropped without any warning. The inner bearing disintergrated causing the axle/hub to crack the housings. Is anyone having this issue? Does anyone drain the Case annually to let fresh fluid drain down from the axle tube? Whenever this happens, its not just Seals and bearings that have to be replaced. Its expensive parts that have been scored up before any signs of bearing failure. Not ho mention the disassembly time to thoroughly clean up the pulverized parts.

 

[number two]

Bummer!
Is he operating with heavy loads in that 724 loader?
And perhaps with no or insufficient counter weight on the 3 point hitch to remove weight from the front axle?
The LA724 is the bigger loader for that tractor,and overloading the front axle sounds real possible.
Good Luck!

 

[Tony H]

Bummer!
Is he operating with heavy loads in that 724 loader?
And perhaps with no or insufficient counter weight on the 3 point hitch to remove weight from the front axle?
The LA724 is the bigger loader for that tractor,and overloading the front axle sounds real possible.
Good Luck!

Heavy loads...yes. That would be my guess. He does move stone, dirt and compost around with only weighted tires. So, no counterbalance on rear wheels. But, our thinking is that if Kubota puts that FEL on that tractor....the tractor, as a stand alone, should be able to handle it.
Last Fall we did make a counterbalance. About 600lbs. Hopefully the future will not see more front end issues.
Bearings are cheap (now that we got the generic part numbers) but the ruined casting and axle parts hurt the wallet when you gotta pay Kubota prices. At least, between the two of us, we can do the work ourselves.

 

[grsthegreat]

Counterbalance is king. I built a 1000# one for mine. The first wrecked housing made me a believer

 

[bdhsfz6]

I haven't had this problem personally, but I've heard of the issue. As a result, I started using high quality 80/90 gear oil in the axle housing. I've read the specs, and people swear by the recommended Kubota SUDT2 hydraulic fluid, but I just don't trust it. It's the consistency of water when hot. The higher viscosity 80/90 oil also helps prevent seal leakage.

I don't overload my FEL, I use counterweights, and I haven't jacked up the pressure to get more lift. I really don't know if the thicker oil is the reason I've had no axle problems, but IMO, it's an ounce of prevention.

 

[5030]

We had to replace a leaking outboard seal on my 2002 M9 Kubota a few months back and the outboard is very heavy as in removal is a 2 man job. The tractor has over 4500 hours on it. 2 years ago the left hand side, we replaced the king pin bushings as they were shot and the radial seals were starting to leak. The opposite side, the bushings were tight but the outboard seal was leaking. It moves and loads round bales every season and never anything weight wise on the back for a counterweight though it also runs the 8 foot shredder as well as the bat wing when required.

The bearings were all in good condition despite the hours. Kind of surprised that Kubota, at least with the bigger units, don't use radial contact roller bearings in the outboards, they are much better suited for load carrying capacity tan the ball bearings Kubota uses. If mine ever fail, I will source radial contact roller bearings to replace the ball bearings.

I always use 85-140 GL4-5 hypoid oil in the front axles on both mine, always have actually. 85-140 is much superior in shock load capability than the UDT or SUDT and shock load capability is important to me in as much as how I use them.

Be apprised that when removing the outboards, they are very heavy and cumbersome to remove and replace and the stub axles are secured with large internal spring clips and external spring clips that entail a set of heavy duty removal tools, not your run of the mill circlip removal pliers nd to that end, I bought a set of internal and external circlip removal tools (Icon) from Harbor Freight. Not cheap, 70 bucks for the pair but a requirement to remove the retaining rings plus the gearing inside the outboard's must be removed with gear pullers to access the seals themselves.

Like I stated, if I have an issue in the future, I'll source radial contact roller bearings to replace the ball bearings simply because the contact surface with the stock ball bearings is much less than with roller bearings. Don't know why Kubota uses ball bearings versus radial contact rollers for the outboards as the roller bearings are superior in every way to the ball bearings. Even if it entails some machining of the castings to accept radial rollers, we can do that here as we have the machine capability to achieve that but in my case the ball bearings were fine. No visible wear at all. It does require a press to reassemble the outboards as well and we have that here also.

Again, I feel that 85-140 gear oil is far superior to to the UDT-SUDT far as shock loading capability is concerned, so that is what I use.

The other somewhat 'odd' things at least with my M9's is, the center section of the front axle is segregated from the outboards with a seal that installs in the center section on each side, behind the removable output shaft and bevel gear that drives the outboards and interestingly, the seal is not called out in the Kubota shop manual. Has to contact my dealer and order it. If your outboards appear to be overfilled, that indicates the seal has failed in the center section axle casting and also needs replaced. I suspect all Kubota tractors with front wheel assist have that seal.

My other issue is the way Kubota vents the axle. There is only ONE vent and it's for the center section and it's kind of hidden up under the center section pivot point. I'm going to machine the top fill plugs on my outboards to accept a vent hose that will allow the outboards to 'breathe' and reduce seal failure.

 

[Chewwy]

If one is doing real heavy FEL work or majority FEL work, one would be better off using an industrial machine. FELs on farm tractors are at best a comprimise.

 

[IndyIan]

Heavy loads...yes. That would be my guess. He does move stone, dirt and compost around with only weighted tires. So, no counterbalance on rear wheels. But, our thinking is that if Kubota puts that FEL on that tractor....the tractor, as a stand alone, should be able to handle it.
Last Fall we did make a counterbalance. About 600lbs. Hopefully the future will not see more front end issues.
Bearings are cheap (now that we got the generic part numbers) but the ruined casting and axle parts hurt the wallet when you gotta pay Kubota prices. At least, between the two of us, we can do the work ourselves.

Yeah, apparently not... I don't know what it would cost to make a front axle nearly unbreakable, but no manufacturer seems to do it. I'd guess the TLB versions have a bit stronger front axles? But if you took the backhoe off, it could load up the front axle more anyways.
I think only a skidsteer is mostly unbreakable as is, but they are dang slow, use lots of fuel, are expensive, no rear pto, and really not good on the lawn...
IMO CUTs are swiss army knives, really handy compared to nothing, but not really good at anything, and you have to work to its limitations. If you're going to be dumb, then you'd better be rich or know how to fix stuff.

 

[sd455dan]

Yeah, apparently not... I don't know what it would cost to make a front axle nearly unbreakable, but no manufacturer seems to do it. I'd guess the TLB versions have a bit stronger front axles? But if you took the backhoe off, it could load up the front axle more anyways.
I think only a skidsteer is mostly unbreakable as is, but they are dang slow, use lots of fuel, are expensive, no rear pto, and really not good on the lawn...
IMO CUTs are swiss army knives, really handy compared to nothing, but not really good at anything, and you have to work to its limitations. If you're going to be dumb, then you'd better be rich or know how to fix stuff.

Keep seeing this on multiple brands, It is usually the same failure mode, and most times it seems to be from the ball bearing cages failing from the load on each ball bearing, once the cage fractures and the balls can migrate around the race it gets ugly quick.

They either need to upsize the bearing which will give more surface area for the larger ball bearings and also a larger stronger cage. Maybe if the ball bearing manufacturers offered a super cage design/ material some of this could be avoided. Or switch like some on this site have suggested a needle roller bearing design instead.

Ball bearings once set loose eat ring and pinions for lunch. This should not be as common as it is because many do keep a good sized load on the 3 point to lower the front axle loading and keep good clean oil in their front axles.

 

[Tony H]

Counterbalance is king. I built a 1000# one for mine. The first wrecked housing made me a believer

Ahhhhh, ive been asking this question since we did the first one on his tractor. Finally someone that had it happen and verifies that counter weight is the way to go. Thanks. What model tractor?
His 600lb-ish one, he says, is borderline for snow plowing. Makes the front, almost too light for turning. Ill convince him to use it in the warm weather when lifting heavy stuff.

 

[grsthegreat]

Ahhhhh, ive been asking this question since we did the first one on his tractor. Finally someone that had it happen and verifies that counter weight is the way to go. Thanks. What model tractor?
His 600lb-ish one, he says, is borderline for snow plowing. Makes the front, almost too light for turning. Ill convince him to use it in the warm weather when lifting heavy stuff.

I have this counterweight on my kioti dk45. Supposed to lift 2700# and i did too much lifting and moving without counterweight. I trashed the front bearings et al.

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[5030]

I do believe that all brands, not just Kubota use ball bearings in the front outboards. In reality they should be angular roller bearings. Like I said, mine are fine and I've had both sides apart on my open station M9 but the ball bearings are the failure point as in too much load on a concentrated area.

Both mine have way more hours on them than most owners put on and I have never had a 'counterweight' on the back except the shredder which isn't back there constantly and both the cab unit as well as the open station move and load round bales every year and my rounds always weigh in the excess of 1000 pounds. Granted, my M's are a bit bigger than most members on here tractors are but I still feel that big or small, the front ends should have roller and not ball bearings.

The other thing about it is, they most likely won't fail while the tractors are under warranty either. Failure is gonna be 'down the road' a bit.

One of the main reasons I run 85-140 gear oil in the front axle. I believe in prevention is better than failure and the 85-140 is at least better shock load prevention than hydraulic oil in m y view. Maybe I'm FOS but I feel better with it in the front axle anyway.

 

[5030]

I have this counterweight on my kioti dk45. Supposed to lift 2700# and i did too much lifting and moving without counterweight. I trashed the front bearings et al.

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Interesting. The front outboards on my M9's are substantially more 'beefier' than yours are. Just removing them take 2 men to manhandle them but regardless, the ball bearings are the weak point. Mine have no less than 26 hex head cap screws holding the outer housing to the inner housing as well. Any way you cut it however, it's a miserable job that should not be in the first place and the parts aren't cheap either.

 

[sd455dan]

Interesting. The front outboards on my M9's are substantially more 'beefier' than yours are. Just removing them take 2 men to manhandle them but regardless, the ball bearings are the weak point. Mine have no less than 26 hex head cap screws holding the outer housing to the inner housing as well. Any way you cut it however, it's a miserable job that should not be in the first place and the parts aren't cheap either.

I had a seal fail on the tractor, outer had a piece of wood stuck in it and inner lip seal was hard so replaced it. Bigger shaft and bearings do seem to help.
I was barely strong enough to put the hub back on but used the backhoe with a chain to lift it off and carry it in to the garage during disassembly.

At over $140 for an SKF bearing wasn't anxious to replace it either.

 

[IndyIan]

Interesting. The front outboards on my M9's are substantially more 'beefier' than yours are. Just removing them take 2 men to manhandle them but regardless, the ball bearings are the weak point. Mine have no less than 26 hex head cap screws holding the outer housing to the inner housing as well. Any way you cut it however, it's a miserable job that should not be in the first place and the parts aren't cheap either.

Yep, it seems the bigger tractors are a bit more robust for their loader capacity. Although I would've thought a M9000 might just have a solid front axle with the yoke and universal joints on the ends? I assume that is a stronger axle design again?
From how I read the tractordata specs, the loader on the 2 ton DKSE series pretty much matches even the loader on the 3 ton M9000, except for lift heights since its a lower tractor. It is kind of a useful feature to have a strong loader on a little tractor, but you have to respect it and how it could break your front axle if you aren't careful.
So far I have no play or issues with my front axle, and I always have a 1000lbs on the back for heavy loader work but I have snuck the a few 800lb bales to the feeders with nothing on the back, or just the lightweight rear blade on for snow... But that's only a 100 yds of going slow.
I do use the full capacity of the loader on occasion, but mostly popping rocks, or stumps out of the ground using the bucket curl, or trying to lift the whole gravel pile at once...

 

[5030]

Because I own a stump grinder, I never 'pop' stumps out of the ground which results in a big hole that needs to be backfilled anyway. I use the loader for it's intended purposes only.

 

[IndyIan]

Because I own a stump grinder, I never 'pop' stumps out of the ground which results in a big hole that needs to be backfilled anyway. I use the loader for it's intended purposes only.

Yep good idea if you got one, although its not so good on rocks.... If I can, I try to leave the loader in float, and use the curl to do the really tough lifting, so I'm not stressing all the expensive parts, although buckets aren't cheap these days either... What I try to do is take the whole small tree at once using the bucket edge to cut roots on 3 sides and push it over, slowly and then push it or carry it to the nearest patch of woods. 8-10" softwoods or junk maples aren't really hard to do with a bit of an edge ground onto the bucket. I'm not digging 20" hard maple stumps, stuff like that gets cut flush or lower with the stumper saw.
So far I've been breakage free, but going slowly and carefully is pretty easy to do with HST. I figure with no impact loading, probably the loader is designed to take whatever loads the cylinders make, or a straight push with the tractor. I've watched guys using construction TLB's hammering them around and if I used my tractor like that, the loader and front axle would be broken pretty fast!

 

[5030]

Good, high quality stump grinders are basically immune to rocks because all the cutter teeth are solid tungsten carbide, least on mine they are and they are indexable to 3 different cutting edge positions. Of course I'm grinding stumps, not cutting concrete.

Why I bought the grinder I bought as the the teeth on the cutter wheel are pretty much industry standard that I can purchase from the manufacturer which is local to me, or off Flea-Bay if I want to and the ones I run are also resharpenable with a diamond wheel of course.

 

[5030]

I own more than one bucket. I have a light duty bucket and a heavy duty double bottom excavation bucket that usually has a hay spear bolted in it. I'm always careful with the light duty bucket, don't want to impart a smile in the bottom. I've repaired more than one smiling bucket in the past for customers and when you put a smile in the bottom, you have to cut both side sheets and then lever (hydraulically) the bottom to make it straight again and then reweld the side sheets to the bottom.

My HD excavation bucket is basically indestructible. It has a double bottom and 3 additional welded in strips on the bottom and the side sheets are 2 times as thick as a light duty bucket. It's heavy though.

 

[5030]

Considering the insane cost of the bearings, you can use the catalog number on the bearings to source any brand you want, including the cheap Chinese ones. Every manufacturer adheres to the catalog numbers on whatever bearings you have.