BX24 diff lock disaster ... How many others have had this problem?

[hodge]

I doubt that Kubota designed the lock with a shear pin. That is not where a weak link would be engineered into the system. It isn't uncommon for a manufacturer to plan for breakage- on a truck, the driveshaft/universal joint is the weak link, and the cheapest to replace. Kubota wouldn't design that into the differential. Therefore, regardless of what caused the breakage, they wouldn't engineer the case to accomodate broken parts. Bad things happen. It is as simple as that. I know that I can't plan for every possible catasrophe in my work- neither can anyone on this forum, and neither can Kubota. It is real easy to blame them for specific, perceived flaws, after the fact. It is entirely another thing to plan for them ahead of time. I feel bad that it happened, but if I were Kubota, I wouldn't take the blame, either.
And, obviously, after 61 responses, not one other person has responded with the same problem- it must be an isolated incident.

 

[David_Kb7uns]

David, did you just chime in now or did you read the thread? Odds are that you CANNOT engage the diff lock at all if you are NOT spinning at least to some degree. You get 2 chances on a spin of the axle to make this happen.

This thread has been around for a while now and I don't recall the exact circumstances, but I don't believe the OP said he was at full throttle, full speed when this happened.

Engaging diff lock lever and advancing until it locks is one thing but I have seen too many people hammer it while rocking pedal back and forth. Of all the times I have gotten stuck the 4 wheel drive does much more then the differential lock in getting out.

Also have read all the wining through the thread been here all the time, there are somethings that you just can not engineering into a product. I have never heard of making space for broken pieces clearance space in the design process.

David Kb7uns

 

[LBrown59]

Quote:
Originally Posted by GolfAddict
On the way up and the way down I'll keep a gentle pressure on the locking lever with my heel. Often it will engage when the high rear wheel starts to loose a bit of traction. The lever will press down and "slip" into diff lock smoothly. So, of course, I am engaging the lock while the wheels are spinning...
didn't realize what a no-no that can be.
I am thinking I'll just use 4wd from now on.

It's right in the owners manual
so I don't know how anyone could miss it.

 

[snort]

I doubt that Kubota designed the lock with a shear pin. That is not where a weak link would be engineered into the system. It isn't uncommon for a manufacturer to plan for breakage- on a truck, the driveshaft/universal joint is the weak link, and the cheapest to replace. Kubota wouldn't design that into the differential. Therefore, regardless of what caused the breakage, they wouldn't engineer the case to accomodate broken parts. Bad things happen. It is as simple as that. I know that I can't plan for every possible catasrophe in my work- neither can anyone on this forum, and neither can Kubota. It is real easy to blame them for specific, perceived flaws, after the fact. It is entirely another thing to plan for them ahead of time. I feel bad that it happened, but if I were Kubota, I wouldn't take the blame, either.
And, obviously, after 61 responses, not one other person has responded with the same problem- it must be an isolated incident.

Hello all,

I've been following this thread and think I've read all the messages. I just bought a BX25 a few months ago. It lives in the garage with a Ford 8N which I've been using for over 30 years. I bought the Kubota because I am getting too "mature" to wrestle with a walk behind blower to clear a kilometer of driveway every time it snows (which it does a lot here in western Newfoundland). The idea of a differential lock seems great but from what I am reading in this thread, misuse of it can be very expensive. I was certainly not warned about how this pedal should be used when I bought the tractor (from Kubota dealer), nor was proper usage or any warnings given in the operator's manual. My question is: can anybody explain under what conditions can the lock be used and how should it be activated? I'm thinking to engage you should be stopped or close to it, rear tires should not be spinning, you should gently put pressure on the pedal until you feel the pin insert/seat itself, locking the differential. Once done, you need to be moving in a straight line. If you need to turn, you should take your foot off the pedal, uncoupling the pin and unlocking the differential. Appreciate it if anyone could confirm or correct my impression.

Best wishes for the new year

 

[GolfAddict]

It's right in the owners manual
so I don't know how anyone could miss it.

OK, dug my owners manual out. The entire section on the differential lock is very brief. A few appropriate safety warnings (the rear wheel are locked, so of course steering is going to be affected) followed by the operation instructions. This is the section of operating instruction verbatim:

If one of the rear wheels should slip, step on the differential lock pedal. Both wheels will then turn together, reducing slippage. Differential lock is maintained only while the pedal is depressed.

That's the extent of the instructions, but there is a follow up Important note and is the only reference of what NOT to do. Again verbatim:

To prevent damage to power train, do not engage differential lock when one wheel is spinning and the other is completely stopped.

So, from what I've read from the various posters here, I think we've all been engaging it and using it appropriately. My "no-no" from earlier turns out not to be a problem, but looks like exactly the correct use.

Hello all,

I've been following this thread and think I've read all the messages. I just bought a BX25 a few months ago. It lives in the garage with a Ford 8N which I've been using for over 30 years. I bought the Kubota because I am getting too "mature" to wrestle with a walk behind blower to clear a kilometer of driveway every time it snows (which it does a lot here in western Newfoundland). The idea of a differential lock seems great but from what I am reading in this thread, misuse of it can be very expensive. I was certainly not warned about how this pedal should be used when I bought the tractor (from Kubota dealer), nor was proper usage or any warnings given in the operator's manual. My question is: can anybody explain under what conditions can the lock be used and how should it be activated? I'm thinking to engage you should be stopped or close to it, rear tires should not be spinning, you should gently put pressure on the pedal until you feel the pin insert/seat itself, locking the differential. Once done, you need to be moving in a straight line. If you need to turn, you should take your foot off the pedal, uncoupling the pin and unlocking the differential. Appreciate it if anyone could confirm or correct my impression.

Best wishes for the new year

Hello snort. I did find the section in the operators manual as mentioned above. From my reading, I think you have it captured pretty much above. I'm thinking that we may not have to be quite so paranoid about using it in the appropriate manner, and poor Carl may have had a very unlucky experience with perhaps a defective lock pin or something...

 

[Grandad4]

I was certainly not warned about how this pedal should be used when I bought the tractor (from Kubota dealer), nor was proper usage or any warnings given in the operator's manual. My question is: can anybody explain under what conditions can the lock be used and how should it be activated? I'm thinking to engage you should be stopped or close to it, rear tires should not be spinning, you should gently put pressure on the pedal until you feel the pin insert/seat itself, locking the differential. Once done, you need to be moving in a straight line. If you need to turn, you should take your foot off the pedal, uncoupling the pin and unlocking the differential. Appreciate it if anyone could confirm or correct my impression.

The diff lock on the BX is pretty much the same as any other tractor... you push a lever to insert a "cog", or pin of some kind between the two opposite sides of the rear differential to join them so they turn together. Obviously, if you do that while one wheel is spinning and the other is stationary, the pin and the gears are going to take a beating. Abuse it often or hard enough and something will break. Kind of reminds me of a high school buddy I knew long ago who was always showing off how he could speed shift his 3 on the tree '59 Ford. He couldn't figure out why he needed to replace the transmission so often!

Take it easy, and it will last forever. I think if you check the owners manual carefully, there should be a section that describes how to operate the diff lock.

 

[radioman]

snort- I think the fears of diff lock breaking on the BX's is overblown here. I use mine every time I "feel" I need it. So use it with caution anytime you want to.

Sometimes when mowing in a ditch and its a bit wet and I want to start to move out and 4 wheel is not engaged, I just simply step on diff and slowly move till it starts to lock rears and its 99% effective getting me out without ripping the lawn or making skid marks. When plowing the snow in 4wd, IF I am in deep heavy snow on grass/dirt and I start drifting or spinning, I just engage my diff lock to get that extra ommph to push. When I was in mud pulling a trailer, all 4's were slipping, and I see my rears is slipping more then other- I engage the diff. :thumbsup:

EVERYTIME- I get myself out of that bad spot- I just thank for the diff lock! I always release it as soon I get out of the bad spot. There is NO need to leave engaged.

It might be me but I still don't understand the fears of diff locks breaking or how it was designed.

 

[Kubota-guy1911]

Hey guys and gals,

In my BX2350 parts exploded view book, looking on page 64 of the differential parts break down, it looks to me like the locking pin is #130. When actuated by the shift fork from the pedal, the pin will fall into the holes in #70 and #120 when they LINE UP, locking them together. Obviously these holes aren't going to be lined up all the time.

I've used my differential lock (on soft ground or icy/snowy condtions) dozens of times and here's how I do it. When stopped, VERY SLOWLY, spin the slipping wheel with LIGHT pressure on the locking pedal. You will feel the locking pin slip right in smoothly and the pedal will go al the way down. You can't force hardened steel parts to move when there is no place for them to go without breaking something.

kj

 

[Doppelgangar]

Good to see some ome looked at the Owners manual and has seen why a lot of you are not reading the owners manual.

The manual does not say to have the tractor stopped or engage the lock when having one wheel spinning. It is clear that you need to put your manual on the internet as then you will have a chance to do some reading.

Dif lock should be engaged when there is slip in one wheel and not the other eg. On the move.
At the time of engagement reduction in power should be undertaken. this will also stop the slipping of the faster wheel.

Power can be restored once the the lock is fully engaged. If tractor is stopped the clutch should be depresed while the engaged processed is undertaken.

Do not jump on the pedel as this will damage other parts.

When pushing snow or going up or down steep grades the diff lock should be in to aid traction. It is not a device to get you unstuck once the tractor has stopped moving. that is what a tow vehicle is used for.

As in one post the author has used the diff lock to stop him leaving skid marks on the lawn.

 

[wcampbell47]

I was at my dealer for some reason and became engaged in a conversation with one of the mechanics - actually the one I prefer to work on my machine. He was repairing an RTV for this very reason. Apparently the drivers continuously stomped on the diff lock while the tires were spinning eventually shearing the pin where it fell through to the bottom and punched a hole in the case.

Problem mostly caused by operator error.

I have been careful with my b7510 and prefer to engage 4WD rather than stomp on the diff lock. Use the diff lock as a last resort.

 

[rascal810]

I was at my dealer for some reason and became engaged in a conversation with one of the mechanics - actually the one I prefer to work on my machine. He was repairing an RTV for this very reason. Apparently the drivers continuously stomped on the diff lock while the tires were spinning eventually shearing the pin where it fell through to the bottom and punched a hole in the case.

Problem mostly caused by operator error.

I have been careful with my b7510 and prefer to engage 4WD rather than stomp on the diff lock. Use the diff lock as a last resort.

Kind of funny you mention this I just posted trying to find some parts for a RTV because of someone doing just what you said. Also I repaired a x740 deere that blew out a side cover when someone engaged the diff lock when one of the wheels was spinning.

 

[oldballs]

Just to add my impressions as a BX owner.....I think "snort" confirmed my understanding. My dealer salesman (an old timer) said to just use the diff-
lock if I got stuck someplace...and to release it as soon as I got "unstuck"...and only go straight...i.e. don't use it in a turn. Thus after almost three years and 270 hours running, I've never used the diff-lock. Four wheel drive has been used a lot however in grading, FEL use and some mowing and towing. If I have to use it some time, I'm going to do it very carefully after I throttle down to idle before engaging.

 

[check]

Just to add my impressions as a BX owner.....I think "snort" confirmed my understanding. My dealer salesman (an old timer) said to just use the diff-
lock if I got stuck someplace...and to release it as soon as I got "unstuck"...and only go straight...i.e. don't use it in a turn. Thus after almost three years and 270 hours running, I've never used the diff-lock. Four wheel drive has been used a lot however in grading, FEL use and some mowing and towing. If I have to use it some time, I'm going to do it very carefully after I throttle down to idle before engaging.

I use the diff lock on my BX25 a LOT, especially when I am digging into a real tough pile of dirt or whatever, or I am on snow or in soft dirt or mud. I think it is one of the great features of the tractor, and it makes a huge difference for me. I also use it mostly when in 4WD (which I am a lot because I have a gravel drive and/or drive in softer dirt/mud or snow). I don't see 4WD as an alternative to diff lock like the other posters here, but rather use diff lock as a supplement to 4WD, because I lose traction very frequently at the cottage, especially when digging with the FEL.

I have also found that diff lock frequently does not engage until you are moving again, sometimes after quite a while (e.g., a few seconds). It is kind of a weird feeling - your foot is resting lightly on the diff lock pedal while you wait for engagement, and then after a bit it decides to drop down softly, presumably as the pin engages. In fact, if I am in a low traction environment, I will just leave the diff lock pedal down continuously while I work, because letting go each time I cycle slows up the work. (e.g., I am spreading gravel, and the gravel surface is of course quite "slippery", so rather than disengage the diff lock after every "shove" into the pile and then re-engaging it again a few seconds later when I return to the pile again to get another bucketfull, I'll just leave the lever depressed. That way I don't have to wait each time I approach the pile while the lever decides when to drop the pin in as I approach (and stop in front of) the pile. All this time I am of course also in 4WD, and I stay there until and unless I get to some firmer ground where I know that 4WD and diff lock will strain the tractor if I make a turn.

 

[CHDinCT]

In fact, if I am in a low traction environment, I will just leave the diff lock pedal down continuously while I work, because letting go each time I cycle slows up the work. (e.g., I am spreading gravel, and the gravel surface is of course quite "slippery", so rather than disengage the diff lock after every "shove" into the pile and then re-engaging it again a few seconds later when I return to the pile again to get another bucketfull, I'll just leave the lever depressed.

I hope you're not making turns while doing this because if you are, your BX might just end up like the OP's with a broken pin or worse. :confused2:

 

[check]

I hope you're not making turns while doing this because if you are, your BX might just end up like the OP's with a broken pin or worse. :confused2:

Only if the ground is slippery!:thumbsup:

 

[rascal810]

I hope you're not making turns while doing this because if you are, your BX might just end up like the OP's with a broken pin or worse. :confused2:

You wont shear the pins once its engaged the problem is engaging it when one wheel is spinning fast and the other is sitting still.

 

[ya472]

Had o-ring leaking hydraulic fluid. Sent to dealer for repair. A week later, more fluid dripping out. Now they say diff lock pin sheared off inside of lower case and punched a hole in lower case. They say repair will be about $3k. Mechanic at dealer says he's done 4 of the this year (it's a small dealer).

I'm thinking this may be a design flaw (for pin failure to cause such catastrophic damage.

If you've had this problem, please contact me. I want to know how common this is.

Carl

I have a 2010 BX25 and for some bizarre reason, the differential lock will engage, possibly with only one pin. ????

Since the axles have to be perfectly aligned to lock the differential, it seems the lock is engaged put the pedal won't go down at first then it does.

When I lift the rear tires off the ground and rattle them back and forth with the lock pedal in the UP position, the differential will unlock, but as soon as I start driving, it partially ??? locks again.

I would like to know how the "Pin, Straight, 2 needed, 37300-28170" stays engaged to the "Shifter, Diff.L , 1 needed K2561-12590" (Coleman Equipment site).

Is there a retainer clip ?

Thx to anyone who has this knowledge, pictures, links or other help.

 

[Tractor Seabee]

Maybe they fixed on the BX25. 1500 hours on mine and no problems so far.

Ron

 

[ralphy711]

I have a 2010 BX25 and for some bizarre reason, the differential lock will engage, possibly with only one pin. ????

Since the axles have to be perfectly aligned to lock the differential, it seems the lock is engaged put the pedal won't go down at first then it does.

When I lift the rear tires off the ground and rattle them back and forth with the lock pedal in the UP position, the differential will unlock, but as soon as I start driving, it partially ??? locks again.

I would like to know how the "Pin, Straight, 2 needed, 37300-28170" stays engaged to the "Shifter, Diff.L , 1 needed K2561-12590" (Coleman Equipment site).

Is there a retainer clip ?

Thx to anyone who has this knowledge, pictures, links or other help.

I'm sure you no longer need the pics... I am about done rebuilding mine and I have plenty. Got my fingers crossed that all is ok.

To anyone using a BX differential lock do so at your own peril. That lock is designed to fail. Total piece of garbage on a couple of levels.

We have three bx's in the family and i will be taking the angle grinder and cutting the pedal off on the two that haven't catastrophically exploded yet. Keep a watch on youtube for video and decide for yourself.

And to those that think the lock will engage without having the wheels turning you are wrong. The only thing saving Kubota on this is that there are a bunch of these machines out there that the owner doesn't even know what that pedal does and they never use it...

 

[Tractor Seabee]

I use the DL quite often on mine. It is cumbersome if the reason to engage it takes some time. My heel tends to slip off that small pedal. Has anyone out there figured a way to engage and hold w/o heel on the pedal. A hand control of push-in/pull out would be handy. Naturally the factory designers have to look at the people factors on these small machines to avoid someone forgetting to disengage or thinking it is OK to leave it that way same as 4WD. Maybe just a larger pedal would help. Have to give that some more thought as it just popped up. Just floating ideas for us more aware operators.

Ron