Kubota BX25 front driveshaft fail.

[@dngendron]

Good thing you found it! I wonder it my skid plate would keep it from at least getting lost.

[@ThisOldMan-ya472]

If you have a look under your tractor, the skid plate probably does not even come close to the front driveshaft.

[@dngendron]

ya472 it does though, I made it myself 😉

[@ThisOldMan-ya472]

@@dngendron Awesome.. If you do Facebook, join the "The Kubota BX'er Network" Forum, and it would be interesting to view pictures of your work if you don't mind posting them.

[@baits9301]

my yanmar 186D has a boot and sleeve so no dust can get in but only has double roll pin for pinion drive shaft connection with no splines .

[@ThisOldMan-ya472]

That seems incredible without splines, but I assume the roll-pins must work for that load. Of course I belong to a couple of Facebook Kubota Forums, so I would not see if there were complaints and problems with the Yanmar. I believe it is a good unit though???

[@davegreenan]

What size is that pin? Same thing just happened to me and I can’t find a pin size anywhere.

[@ThisOldMan-ya472]

It is metric, I believe 8mm, so I just installed a stainless steel bolt with a Nylock nut.

[@davegreenan]

@@ThisOldMan-ya472 ahhh thank you! I’ve been pretty lucky with my BX2360. In ten years this is the first issue!

[@ThisOldMan-ya472]

@@davegreenan I work my BX25 to the max, and have broken many things, but since I can repair almost everything, or replace, the BX just keeps going with over 3300 hours now.

[@davegreenan]

@@ThisOldMan-ya472 I will definitely buy another one again. Thanks for the video and may you get a million hours out of yours!

[@MDR-hn2yz]

I just had the same problem and my drive shaft doesn’t want to go back together.

[@ThisOldMan-ya472]

What will not go back together, the spline shaft? It only goes on one way, so it lines up the universal joints for balance. Be sure the splines are clean and use "dry lubricant."

[@MDR-hn2yz]

@@ThisOldMan-ya472 Yeah. I couldn’t get the rear end of the drive shaft into the universal joint. Like you said “clean and lubed”. Mine wasn’t. All good now. Happy new year.

[@ThisOldMan-ya472]

@@MDR-hn2yz Awesome. Happy New Year!

[@jj1479]

If the pin was never in there it the shaft would of fell off within minutes. The cover part# K2511-1685 is $15.73 an the pin joint part# K2561-16782 is $1.02 at Messick’s

[@ThisOldMan-ya472]

It is a mystery how that pin would fail. :-)

[@hermzinn8740]

If you hold one of your front wheels so it can't turn and turn the other wheel the spline where the driveshaft hooks will turn at a steady speed with the wheel. That is because the front diff is an open diff and not posi traction. If the front diff were posi traction you would not be able to turn around corners. It would just want to go straight.

[@ThisOldMan-ya472]

You are correct. However, in the video, my point was that I was watching the pinion shaft turn, and yet not realizing the driveshaft was off. I was listening for odd noises, like clicking. lol

[@bluegrassboy]

I break that roll pin at least once a year.

[@ThisOldMan-ya472]

Recently mine broke again. As usual, it was buried in the mud. :-)

[@SlackerU]

You should spray that thing with oil more often, & put some real TLC time in with grease. Sure the manual doesn't say to grease that shafts but if the other shafts require greasing every 50hrs then you shouldn't have so much dry rust on that one. 1:26 2100hrs though, geez you've got your moneys worth either way.

[@ThisOldMan-ya472]

Now over 2400 hours. Thx. I recently learned in some applications, grease is the wrong thing to use because it impacts with dirt and the oils dry out, so unless you maintain it with regular greasings, it is much better to use either applications of light oil, or a dry lubricant, even silicone lube. ??? Initially I never paid attention to the front driveshaft, as it looked self contained (sealed) and did not notice lubrication recommendation in the manual.

[@SlackerU]

@@ThisOldMan-ya472 With a needle point greasing tip you can get grease in tight spaces. Any time I see dry rust on mine the entire tractor gets a spray down of mineral oil like WD40. The splines on those shafts would benefit from a moly grease application like what is recommended in Land Pride attachment manuals. It may be too late to bother unless you expect to get another 2k worth of work out of it. All exposed stainless on spaceships get a weekly application of WD40.

[@ThisOldMan-ya472]

@@SlackerU Spline rust is not much of a concern, as long as the parts move. I have greater issues with pin rust on the FEL and backhoe.. a real pain in the butt, as moisture gets trapped.

[@SlackerU]

@@ThisOldMan-ya472 The splines on my mid mount mower driveshaft requires a greasing so it just feels odd for me to not also apply a good greasing to the 4x4 splines as well. Greasing the 4x4 shaft also reduces a clicking I can sometimes hear.

[@ThisOldMan-ya472]

@@SlackerU Good points.. I should re-visit this issue as the BX25 is overdue for an oil change too.

[@travelandwork]

Mine failed too..

[@ThisOldMan-ya472]

Such a common problem, but no real answer as to why. Maybe under a heavy pushing load, when the axle swings, the spline that should move doesn't, and at the other spline, the pin snaps?

[@ThisOldMan-ya472]

Maybe the solution is more frequent light oiling?

[@travelandwork]

@@ThisOldMan-ya472 Honestly the plastic boot was all mangled up.. not that it would cause this..but it just shows how hard I am on this poor thing..I REALLY ABUSE IT. Im surprised it lasted for almost 3 years before that failed...

[@ThisOldMan-ya472]

@@travelandwork I do not abuse my little BX25, but I use it harder than most people I know. LOL 2439 hours now.

[@organicvids]

Poor design dealing with same issue. The driveshaft is too steep going into front axle. Oscilates n wears gears prematurely. Expensive fix.

[@ThisOldMan-ya472]

Yes and no. The problem is the steep angle when the front axle pivots under a loaded FEL, and snaps the retaining pin. I just broke another two days ago, and today, I went and bought FOUR 6 x 50 mm bolts and Nylock nuts for constant replacement. Keeping the splines clean and lubricated is necessary. I will ADD a grease nipple soon, before I break those four pins.

[@ThisOldMan-ya472]

I have 3170 hours, low front axle oil, never added any, and never had front gear problems. hmmm

[@organicvids]

Ill do a vid when i put mine back together​@@ThisOldMan-ya472

[@ThisOldMan-ya472]

@@organicvids A video would be awesome. I have been very lax about the front axle oil level, which I really need to address, and probably need seals. Your video would be very helpful. Thx.

[@davidradzieta6458]

Rotate the boot half an inch and drill a new hole.

[@ThisOldMan-ya472]

Good idea if the boot is still serviceable. I never replaced mine (they are not expensive when I last checked) and I have not seen any benefit for the boot, other than appearance.

[@91rss]

that poor machine needs a going over, thats the worse shaft condition I ever saw. Self inflicted no pity on that one..

[@ThisOldMan-ya472]

What are you talking about? The shaft is fine, not bent, but does have 2300 hours use, and it does work hard. It doesn't have to look pretty. LOL

[@91rss]

@@ThisOldMan-ya472 look at the rust on the splines. thats the worst I've seen in my 40 yrs of repairing things

[@ThisOldMan-ya472]

@@91rss Yes, there is surface rust on the exposed metal. How would you control that? This tractor lives outdoors, grease and oil will just cake with grit, which would be worse, and I suppose one could paint it. I am open to suggestions, however, that skim of rust isn't severe, or hurting anything. ??? You should see the rest of the tractor, especially the backhoe, it is a scraped paint mess. lol

[@91rss]

@@ThisOldMan-ya472 the splines need greasing, the best grease has moly in it. Like Caterpillar grease. and when regreased, dont wash splines with mineral spirits unless you clean that off with brake clean etc as spirits have a film so grease cant do its job.

[@ThisOldMan-ya472]

@@91rss I will check the Service Manual, because my splined joints do not have a grease nipple. It doesn't look like it ever had grease on it, because I never greased it. There must be something in the maintenance schedule?