Differential Lock

BotaLoda

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BX2370, Loader w/tooth bar, MMM, sub soiler, 5' rake, rear ballast box, forks.
Feb 28, 2017
120
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16
Cosby, TN
If your having that issue you don't have enough rear ballast!
I sort of knew someone was going to tell me that. It would be a real nuisance to put the ballast on for 10 minutes of mowing then taking it off. And I was being a bit dramatic about how bad that problem is, it's only if I go too fast which I don't do anymore anyway.
 

BotaLoda

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Equipment
BX2370, Loader w/tooth bar, MMM, sub soiler, 5' rake, rear ballast box, forks.
Feb 28, 2017
120
0
16
Cosby, TN
Think I'd get a bigger tractor.
When I bought it I was only shopping for a lawn mower, for which it's oversized for that job. Getting it with a loader has me doing a lot of things I never could have done with a lawn mower, but a bigger tractor is out of my budget, in fact the same size new with a backhoe is way out of my budget.

I think the biggest problem is that when first buying it, they told me I could do some decent digging if I got a tooth bar. I think they steered me wrong there. I should have gone all out and got one with a backhoe. Don't all jump on my *** about trying to dig with the FEL, I know now. Besides lot's of people here told me about the ?shark bite? teeth that dig so well and no one told me to go easy on it. I don't need a scolding, looking at those parts that broke told me enough.
 

BotaLoda

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Equipment
BX2370, Loader w/tooth bar, MMM, sub soiler, 5' rake, rear ballast box, forks.
Feb 28, 2017
120
0
16
Cosby, TN
I don***8217;t know, but 4 5/16***8221; pins in shear mode are really strong, even with a gap.

I***8217;m guessing the higher breakage rate of diff lock on the bx is more due the bx having a higher occurrence of inexperienced operators than the hardware not strong enough.
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If those 4 pins had been located around a larger diameter area, yes they would be strong. But they aren't, I don't have that in front of me now but the holes in the spider gear are pretty close together. The smaller the radius of those pins is exponentially weaker the smaller the radius, and the same goes for the distance between where the pins are mounted to where they engage. If it were tight against I highly doubt they would have broke, not yet anyway, not in a long time. Really wish I had taken pics of those parts, but I think the radius of pin location is only about 2". That spells disaster. A larger radius means more leverage and much less pressure on those pins.

Inexperienced? Yes, without a doubt. I overworked it because I was told it could take it, now I know better. I was sold a tractor that could do some serious digging with a tooth bar, now I know better and will go much easier on it.
 
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D2Cat

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L305DT, B7100HST, TG1860, TG1860D, L4240
Mar 27, 2014
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BotaLoda remember, if those pins were built larger in dia. to hold more pressure, and you continued using it as you were....what would have broken then?

When any machine/tool is used beyond it's capacity something gives up. Your situation is very, very rare in Kubota tractors. You were just misguided in the use of your tractor. Take the new knowledge and use it accordingly, you'll be fine from now on!

And if you're not sure about something, just ask before attempting. Someone will help.
 

BotaLoda

Member

Equipment
BX2370, Loader w/tooth bar, MMM, sub soiler, 5' rake, rear ballast box, forks.
Feb 28, 2017
120
0
16
Cosby, TN
BotaLoda remember, if those pins were built larger in dia. to hold more pressure, and you continued using it as you were....what would have broken then?

When any machine/tool is used beyond it's capacity something gives up. Your situation is very, very rare in Kubota tractors. You were just misguided in the use of your tractor. Take the new knowledge and use it accordingly, you'll be fine from now on!

And if you're not sure about something, just ask before attempting. Someone will help.
D2Cat, with the question of what else would break if the pins didn't, it made me think of my 55 chevy hot rod. I put a newer "12 bolt" rear/transaxle in it to handle the power/torque of the motor. Trying to compare it to the locking rear isn't really that great of a comparison since it doesn't have a differential lock, BUT... the gears in it are strong. The weakest link right now is the axles. I first had some really crappy ones a shop stuck me with and I twisted an axle from taking off at the drag races. Never would have known it if I hadn't been taking it apart to change gear ratio. Eventually the axle could have twisted enough to break, it happens. Luckily the repair if I was paying a shop, would be about $500 with parts on the high side. (I don't have C-clips if you know what they are). So anyway, if the axle were the weak link on the tractor, it also would be a repair of no more than half of what this warranty work would have cost me. That's if the info to pull an axle on the BX is correct. The unit would not have to be split in half, much less labor and less parts. Actually I just looked somewhere else and it looks even easier than I thought to replace an axle. $235 for the axle and some more for a seal. Less than an hour for a pro and 2 hours for me, instead of 12 hours (which the mechanic must have been good to do that in 12 hours!).
Sorry this go so so long. To make a long story short, put the cheap parts where they are easy to replace!

Trust me, that diff lock will be babied from now on. If out of warranty that job would probably take me a good 40 hours instead of 12.
 

BotaLoda

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BX2370, Loader w/tooth bar, MMM, sub soiler, 5' rake, rear ballast box, forks.
Feb 28, 2017
120
0
16
Cosby, TN
The rain let up enough yesterday to mow part of my yard and all of my lady friend's lawn. Put it in and out of diff lock a bunch of times just to try it, and you know, in some situations it will still be a PITA to get it out of lock when heading for a hard surface. Maybe I'll get lucky and it will get *broken in* a little?

Forgot to add, the hydro pedal sticks and the mmm raise and lower lever sticks. I'll have to see if I can fit them, it's a long ride to the dealer and back.
 
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troverman

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MX6000 HSTC; 2020 Kubota Z421KW-54 zero turn mower
Jun 9, 2015
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When going down a steep grade, using 4x4 is appropriate. Not on pavement, but if the back end is really light than using 4x4 is probably fine since the back end can slip anyway. Weight transfer always goes to the downhill side, so all the pressure is on the front when you head downhill. There are no brakes on the front, so engaging 4x4 basically "adds" brakes to the front, if that makes sense.
 

BotaLoda

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BX2370, Loader w/tooth bar, MMM, sub soiler, 5' rake, rear ballast box, forks.
Feb 28, 2017
120
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16
Cosby, TN
Yes, that makes perfect sense. Actually none of the *wheels* have brakes, just the drive system.

If I'm in that situation, I normally put it into 4wd, I was just checking to be sure.
 

troverman

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MX6000 HSTC; 2020 Kubota Z421KW-54 zero turn mower
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Actually none of the *wheels* have brakes, just the drive system.
Well, they are just inboard wet disc brakes. A few vehicles also use inboard disc brakes, such as mid 1990's and back Jaguar XJ's, and the Humvees. With brakes firmly applied, though, both rear tires should stop and if there is not enough weight on the back for traction, they should both skid, not turn in opposite directions.
 

beex

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May 21, 2019
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Well, they are just inboard wet disc brakes. A few vehicles also use inboard disc brakes, such as mid 1990's and back Jaguar XJ's, and the Humvees. With brakes firmly applied, though, both rear tires should stop and if there is not enough weight on the back for traction, they should both skid, not turn in opposite directions.


It’s not an inboard vs outboard issue, it’s upstream vs downstream of the differential issue. the Jag XJ and Humvees.. have inboard breaks, but downstream of the differential. There is a brake on each axle. doesn’t matter where on the axle it is. An internal brake upstream from to the differential, like the BX and all other SCUTs, there is one brake on the drive system that works though the differential, so the differential can still do it’s thing. Jack up the backend put the brakes on and turn one wheel, the other will go in the opposite at the same speed. Same as the front wheels if you put it in 4wd.


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troverman

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MX6000 HSTC; 2020 Kubota Z421KW-54 zero turn mower
Jun 9, 2015
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Maybe I'm missing something. How does a tractor have a "left" and "right" brake if there is only one disc upstream of the diff?
 

beex

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May 21, 2019
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Maybe I'm missing something. How does a tractor have a "left" and "right" brake if there is only one disc upstream of the diff?


SCUTs don’t have left and right brakes. CUTs do, and they are internal wet brakes, and downstream of the differential.


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troverman

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I'm seeing the error of my ways...apparently the BX tractors only have one brake. Hmm, even the B-series had dual brakes, I guess I assumed the BX did as well.

OK, then that makes sense.
 

beex

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May 21, 2019
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I'm seeing the error of my ways...apparently the BX tractors only have one brake. Hmm, even the B-series had dual brakes, I guess I assumed the BX did as well.



OK, then that makes sense.


Yes everything bigger than a SCUT has split brakes, some people call them steering brakes. SCUTs don’t really need them because they turn tight without them, and it reduces cost to not have them, and the average SCUT user wouldn’t ever use them as split brakes. A lot of CUT users don’t use them as steering either.


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troverman

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MX6000 HSTC; 2020 Kubota Z421KW-54 zero turn mower
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And all that makes sense too. Frankly, many of the Kubotas have their split brake pedals in a position that basically makes them impossible to use as well.
 

beex

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May 21, 2019
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And all that makes sense too. Frankly, many of the Kubotas have their split brake pedals in a position that basically makes them impossible to use as well.


Yes, i wish they would fix that. It’s on the models that come with gear drive or HST, like the smaller standard L models. Gear drive you want split brakes on the right, HST on the left. But the standard L models are lower cost, trying to keep costs down, so they don’t have a configuration with left brakes. But they should, I bet 95% of the CUTs they sell, even in standard Ls are HSTs.


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troverman

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Yep, my brand new L2501 has the dual brakes in a useless position above the HST pedal. You could apply them with cruise control active, but my 2501 doesn't have cruise.

Now, they *have* corrected this problem on the B-series, the brakes are on the left now. And my MX4800 HST has the brakes on the left as well.

The real reason is because the standard L tractors (4701 aside) still have mechanically-engaged PTOs that require a clutch. So, the clutch pedal even on an HST tractor resides in the space the brakes would be.
 

BotaLoda

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BX2370, Loader w/tooth bar, MMM, sub soiler, 5' rake, rear ballast box, forks.
Feb 28, 2017
120
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16
Cosby, TN
It’s not an inboard vs outboard issue, it’s upstream vs downstream of the differential issue. the Jag XJ and Humvees.. have inboard breaks, but downstream of the differential. There is a brake on each axle. doesn’t matter where on the axle it is. An internal brake upstream from to the differential, like the BX and all other SCUTs, there is one brake on the drive system that works though the differential, so the differential can still do it’s thing. Jack up the backend put the brakes on and turn one wheel, the other will go in the opposite at the same speed. Same as the front wheels if you put it in 4wd.


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Exactly.
A separate brake/pedal for each side would be nice, it sure makes sharp turns in mud easier. I used to use them on my old neighbors big yellow JD loader/hoe
 

beex

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May 21, 2019
312
5
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on my bx
Yep, my brand new L2501 has the dual brakes in a useless position above the HST pedal. You could apply them with cruise control active, but my 2501 doesn't have cruise.



Now, they *have* corrected this problem on the B-series, the brakes are on the left now. And my MX4800 HST has the brakes on the left as well.



The real reason is because the standard L tractors (4701 aside) still have mechanically-engaged PTOs that require a clutch. So, the clutch pedal even on an HST tractor resides in the space the brakes would be.


Yes, the PTO needs its own hand operated clutch, or an hydraulic clutch/lever, like the Bs, the HST doesn’t need a foot operated clutch. If they did this on the L2501 so it’s like a B2601, it would be perfect. The B series is too narrow too tippy for me to call it perfect.

Also if you have usable split breaks, you don’t need to use the diff lock as much, you, just brake the spinning tire, you get unstuck, let the brake off, it’s fast, easy.


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shootem604

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L245DT with Kubota (Arps Model 22) FEL and Kubota B/L4520B (Woods 650) BH
Apr 23, 2018
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British Columbia
The steering brakes come in handy too if you have a heavy boulder the grip of your BH thumb and need to go across the yard with the front end to light to steer nicely...
 
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