B26 repair of broken u-joint on front drive shaft at HST output

[SamWalton]

This U-joint failed and it looks like the repair is super expensive. I have been looking at alternatives to such a labor intensive repair. I am considering cutting out an opening in the plat from the bottom after removing the HST oil tank. Possibly using a plasma cutter to open for repair. This would make it easy to push out pins to remove U-joint. Two large bolts can be removed which support the front axel and wheels. This could give the extra movment of the drive shaft to allow removal and installation of the new U-joint. I am not sure if this will work but the photos and drawing look to support this theory. I have attached pictures and parts diagrams to show how these thing come together. Please, anyone who has done this repair, via dealer or otherwise please share your thoughts and opinions.

I have called the service department of our local Kubota dealer and they are unwilling to provide details on this repair. Also the service manual is not available on the internet and I may purchase a hard copy from the dealer.

 

[RalphVa]

How many hours on it? FINALLY hear about another tractor other than JD with failed Ujoint. The one on the engine side of my 4010 JD failed at 660 hours. After that, JD advised greasing them every 50 hours, but you cannot get to the front one. Had the one on the 2025R greased at 200 hours by JD. They had to remove the instrument panel. Removed whole driveshaft because you cannot even get a gun on the rear one unless it is bent 90 degrees.

You don't show any possible access from the top. Bet that is how you get to it. That's how they got the 4010's out. Saw it in the shop. I just traded for the next tractor then.

 

[CoyPatton]

I have no ideal how to do your repair.
A few observations from your pictures.
1) your U-joint appears to be full of crud. Even if it is grease from greasing the U-joint(s), if operated in cooler temps and depending on the grease compounds, grease can get very hard just by themselves, add in some dirt and grit from normal operating and you could have it bound up with very solid wad of whatever contributing to failure.
2) not being able to see what is ‘above’ the HST tank or what might be above the plate you plan to cut out, caution with flames when cutting is a HUGE MUST!
3) again a safety caution. Many jack stands have been recalled. Many more are suspect that have not been recalled. Many people are suggesting using various types of blocking material, be aware that every time you put a block on top of a block, you add a potential shift point. Also bases of any support system needs to be on solid non-shifting/moving surface.

 

[Username Taken]

Good luck. I went through this on a JD 2305. Took days to get to the driveshaft and remove it only to discover the cardan joint had been fatally damaged by the U-Joint coming apart. Took it to a driveline repair shop and discovered that JD uses a proprietary (shock!) spline that fits JD, and only JD, PTO shafts. And they wanted $800 for a new one. I was lucky to find that one. A normal repair on a normal driveshaft with standard splines would have been around $100, maybe a little more with balancing, etc.

Went in from the top, removing the seat, the floorboard, the steering wheel and a bunch of other stoopid stuff. It was nutz. Days and days of re-inventing the wheel.

The point of this post isn't to tell you about my troubles but to tell you to not wait until the u-joint destroys the cardan joint, or the yoke.

I don't blame the Dealer for not telling you how to fix it. At all. It's where they make their money, not on new tractor sales. How much are they quoting you?? In hindsight, I would have paid $500 for the fix, if I had it to do over again, but it was easier to sell that piece of junk, after we welded the joint up a bit, to one of the locals who thinks green and yellow is anything but ugly. Told him about the troubles up front, he didn't care.

My next one will be orange. I'm done with people who manufacture goods that only their parts will fit. Not so much that it broke. EVERYTHING breaks, but that you gotta pay through the nose for a one-off design that is no improvement whatsoever over standard. JD loves to do that

 

[ruffdog]

Other threads:

B26 Kubota Front Yoke Replacemant Help.

 

[dfkrug]

I recently split and reassembled a B20. There are more similarities to the B26 than I would have expected. The tunnel section on mine has 2 hatches on the top, and one on each the left side and the bottom. This allows access to the main shaft U-joint, but the MFWD coupler is harder to access.

I see the B26 has gone to double roll pins from the single pin + wire on the B20. The B21 does it like the B26. I noticed that my U-joint roll pin had broken, tho it had not come apart yet.

I think you should cut a hole. Splitting the B20 was a huge project, as was the B21 I did years ago.

 

[RalphVa]

Think they should use these in place of the Ujoints: Mercedes Driveshaft Flex Joint (ML350) - Febi 1644100015

Was what was between the shaft and the transmission on our 1983 240D stick.

There's hardly any movement needed.

 

[ruffdog]

^^^...my Cub Cadet too.

 

[SamWalton]

I have no ideal how to do your repair.
A few observations from your pictures.
1) your U-joint appears to be full of crud. Even if it is grease from greasing the U-joint(s), if operated in cooler temps and depending on the grease compounds, grease can get very hard just by themselves, add in some dirt and grit from normal operating and you could have it bound up with very solid wad of whatever contributing to failure.
2) not being able to see what is ‘above’ the HST tank or what might be above the plate you plan to cut out, caution with flames when cutting is a HUGE MUST!
3) again a safety caution. Many jack stands have been recalled. Many more are suspect that have not been recalled. Many people are suggesting using various types of blocking material, be aware that every time you put a block on top of a block, you add a potential shift point. Also bases of any support system needs to be on solid non-shifting/moving

Great safety observations. Thanks. I have been considering the many safety issues. Each and every time I work around high risk activities.

How many hours on it? FINALLY hear about another tractor other than JD with failed Ujoint. The one on the engine side of my 4010 JD failed at 660 hours. After that, JD advised greasing them every 50 hours, but you cannot get to the front one. Had the one on the 2025R greased at 200 hours by JD. They had to remove the instrument panel. Removed whole driveshaft because you cannot even get a gun on the rear one unless it is bent 90 degrees.

You don't show any possible access from the top. Bet that is how you get to it. That's how they got the 4010's out. Saw it in the shop. I just traded for the next tractor then.

800 hours

 

[SamWalton]

I recently split and reassembled a B20. There are more similarities to the B26 than I would have expected. The tunnel section on mine has 2 hatches on the top, and one on each the left side and the bottom. This allows access to the main shaft U-joint, but the MFWD coupler is harder to access.

I see the B26 has gone to double roll pins from the single pin + wire on the B20. The B21 does it like the B26. I noticed that my U-joint roll pin had broken, tho it had not come apart yet.

I think you should cut a hole. Splitting the B20 was a huge project, as was the B21 I did years ago.

If I pulled the front axel forward the drive shaft should come out completely. If broken and I could learn if the U-joint broke or fell off which would allow you to know if the spline Shaft could be damaged?

 

[Username Taken]

If I pulled the front axel forward the drive shaft should come out completely. If broken and I could learn if the U-joint broke or fell off which would allow you to know if the spline Shaft could be damaged?

I would think that if the U-Joint bearing fell apart and it was beating the daylights out of the yoke, you would have heard it.

 

[dfkrug]

If I pulled the front axel forward the drive shaft should come out completely. If broken and I could learn if the U-joint broke or fell off which would allow you to know if the spline Shaft could be damaged?

The MFWD driveshaft on the B26 looks about the same as what I have on the B20. You can just remove the front axle assembly, as you said, and slide the shaft forward and out. You should be able to see inside the tunnel a little better, plus determine the health of your shaft.

The shaft uses a sliding seal, with brass bearing. I replaced mine.

 

[SamWalton]

I purchased the shop manual for $82. Some of the pictures are helpful. The dealer quoted 11 hours at $100 and the U-joint for $1200. The front axel can be removed to avoid splitting the tractor but a large hole must be cut out to replace the U-joint. Pics attached Any options please. Thanks

 

[SamWalton]

More pics

 

[SamWalton]

The MFWD driveshaft on the B26 looks about the same as what I have on the B20. You can just remove the front axle assembly, as you said, and slide the shaft forward and out. You should be able to see inside the tunnel a little better, plus determine the health of your shaft.

The shaft uses a sliding seal, with brass bearing. I replaced mine.

I put a flexible camera in to look but it was not a wide angle. I didn't get any clear evidence other than it looks broken and the shaft is no longer connected.

 

[dfkrug]

Are you going to take this on yourself, Sam? A smooth and flat floor indoors is a necessity, IMO.

If you can avoid splitting, that is good. You may not be able to avoid removing the "main frame". This is the part that adds so much work vs. a normal CUT.

 

[ruffdog]

Well Sam, being that the coupler/yoke/joint/shaft is broken or damaged, I would be leaning towards splitting the tractor. If you remove the front axle and find there is damage back at the HST you need to fix, you will have to install the axle and split it anyways.

 

[SamWalton]

Are you going to take this on yourself, Sam? A smooth and flat floor indoors is a necessity, IMO.

If you can avoid splitting, that is good. You may not be able to avoid removing the "main frame". This is the part that adds so much work vs. a normal CUT.

Unfortunately this repair will be outside on gravel. I believe the front axel may need to be remove to provide room for the repaired axel to get between it's connections. It may be possible to remove the frame mounting at the u-joint closer to the axel and flex to shorten the distance. Cutting a large opening at the HST plate will allow the pin installation to secure the u-joint.

 

[SamWalton]

Well Sam, being that the coupler/yoke/joint/shaft is broken or damaged, I would be leaning towards splitting the tractor. If you remove the front axle and find there is damage back at the HST you need to fix, you will have to install the axle and split it anyways.

You are correct. I should get a good view to assess damage if I can remove the broken drive

 

[Username Taken]

Does the driveshaft have a slip joint to allow for suspension travel?