Bent mid PTO for snowblower

[asgard]

Well, today was a real highlight moment.
After a fall of 6 inches of light snow, I decided to blow it using my twice used new front blower. All went well at the start and it did a good job, however, as I approached the 25-minute mark and blowing just 6 inches of snow the universal coupling at the PTO drive end let go, snapped and sent the shaft flying.
Well. it flew into the cross member, then left the snowblower coupling.
It is a horrific noise and then you think what happened as you drive over the shaft lying now behind you.
Snow blower is fine, all shear pins intact rotates easily by hand, PTO splines are ok on both blower and tractor.
So the damage is to one universal coupling, one of the cups is completely missing, the other is sheared off. Tube, is bent with a good sized dent.
Anyone else had any issue with this blower? It has operated for about 1 hour, installed by the dealer.

 

[Emoo]

I just did that exact same thing and on here looking for the part number to replace the shaft.. Mind was stuck between the frame and rear wheel. The snowblower frame mounted portion lost a bolt and the shaft let loose with a terrible sound , it didnt snap but is FUBAR

 

[Southernfarm]

Mid PTO kit, Driveline Part # 70060-02186

Complete with two universal joints and couplers on each end.

This is for the Mid PTO kit that I have on a BX25 for the BX2750 blower. Just reading you have a B series.

 

[Dave_eng]

Well, today was a real highlight moment.
After a fall of 6 inches of light snow, I decided to blow it using my twice used new front blower. All went well at the start and it did a good job, however, as I approached the 25-minute mark and blowing just 6 inches of snow the universal coupling at the PTO drive end let go, snapped and sent the shaft flying.
Well. it flew into the cross member, then left the snowblower coupling.
It is a horrific noise and then you think what happened as you drive over the shaft lying now behind you.
Snow blower is fine, all shear pins intact rotates easily by hand, PTO splines are ok on both blower and tractor.
So the damage is to one universal coupling, one of the cups is completely missing, the other is sheared off. Tube, is bent with a good sized dent.
Anyone else had any issue with this blower? It has operated for about 1 hour, installed by the dealer.

Friend in Ottawa Ontario had front mounted blower installed. Dealer installed blower made for a newer tractor and pto shaft was hitting tractor frame. When blower was raised the pto was rubbing on the frame.

He was lucky he heard the noise before he experienced what you did.

PTO shafts wont stand for any sideways pressure. Also check that shaft does not bottom out at any point in raising and lowering and has sufficient overlap. Unless your dealer has a good explanation for the failure you need to double check his work and not just put on another new pto shaft.

Look at the red arrow in your photo which I have marked up. Could it correspond to something on the tractor frame? The mark looks like it happened while the shaft was stationary. The first time the blower was raised the shaft was bent and destined to fail.

Large trucks put steel loops around their drive shafts to limit how far they can swing when they fail. You might consider doing this too.

Dave M7040

 

[asgard]

Well, the blower is listed on the available accessories for the B01 series tractor so I think that is not an issue.

The fact it runs between two fixed points and that I don't believe that shaft alters in axis, the PTO on the tractor is a fixed point and the splined shaft is fixed by the quick attach unit.

The bend and dent were as a result of it hitting the spreader plate between the frame rails beside the engine sump. Only other marks are some deep scratches and small burrs on the quick attach plate ends.

Rechecking the dealer install is on my list, but I will be asking them to send out a tech. Tractor has less than 3 hours on the clock. They fitted it, they can check it, I will not be assuming any liability.

Spoken to my sales rep and will contact the service manager tomorrow. Was told this was not common and warrantied. We will find out.

 

[Southernfarm]

Yes their fault for sure. But with a mid pto kit, there is travel at the front knuckle joint as you raise and lower the blower. There could still be some binding there when the blower is fully up and the PTO is engaged as others have mentioned.

 

[OrangeLivin]

Wow I've never seen something like that, and can't imagine the noise it made when it let go. Thankfully no one was hurt - I might've had a coronary from fear when that thing started making a racket! Hopefully the dealer is able to fix it so it doesn't happen again.

 

[Lil Foot]

I wonder if one of the bearing cup retainer clips was missing? Saw a similar result with a rock crawler driveline that was just replaced- when he got back to the shop, one of the clips was still laying on the bench where he had assembled the driveline.

 

[asgard]

Lil Foot, I think you win the prize for most likely answer to the issue.

On further inspection, it looks very much like one of the clips came loose or was missing. One caps came out and allowed the shaft to rotate out of axis and shear the opposite post.
After that is was toast.
Dealer, has never seen this before and is ordering in a new shaft.

This is on inspection a very flimsy item, the couplings are very small, the shaft tube is again thin walled. It wouldn't have killed them to make both the couplings and the shaft a bit more robust, after al,l it is a short shaft, the weight would not be that much if an issue and the balance might have been better.

 

[Thorny]

If you are concerned about the quality of the shaft, you could order a replacement from outside of the OEM and probably get much better quality.

Back to the "rock crawler" comment above, I used to play in that world and had Woody's make me a driveshaft that was simply bombproof for a few hundred bucks. You tell him the CV joint size, the length needed and and restrictions that you've got (like shaft diameter that will fit in your space) and let him make you a beefier one. you probably have a local driveline guy who could do the same thing.

 

[NoJacketRequired]

Back to the "rock crawler" comment above, I used to play in that world and had Woody's make me a driveshaft that was simply bombproof for a few hundred bucks. You tell him the CV joint size, the length needed and and restrictions that you've got (like shaft diameter that will fit in your space) and let him make you a beefier one. you probably have a local driveline guy who could do the same thing.

This comment reflects a thought that's been rattling around in my little pea brain since bringing our "new to us" B7510 and front mount blower home the first time. That PTO shaft is spinning fast. The short shaft that joins the output of the under-frame adapter to the blower itself is always running on an angle because of the chain speed reduction on the blower. This seems like an excellent application for a CV joint rather than a U-joint.

Am I nuts in thinking this?

BTW, an earlier comment talked about the shaft being able to touch other parts of the tractor or mount. I know with our setup, the plastic sheath on that forward-most shaft can and indeed does touch the left hand vertical support member of the front mount adapter. If I raise the blower too far, I can hear and feel it touching so I lower the blower an inch or so and the noise/vibration goes away. Seems Kubota cut things a little too close in this particular installation. Per Kubota documentation verified by the dealer while I watched, the mount and blower are both the correct parts for this tractor.

All of this makes me think about changing out the chain reduction drive for a gearbox so the PTO shaft would run straight forward into the blower, rather than being offset to the left all the time.

 

[RCW]

The fact it runs between two fixed points and that I don't believe that shaft alters in axis, the PTO on the tractor is a fixed point and the splined shaft is fixed by the quick attach unit.

I wonder if one of the bearing cup retainer clips was missing?

Having a similar setup on a BX, I think you guys are right on.

That shaft is fixed front and rear - should be virtually no movement....no reason movement of the blower itself would have an effect on that shaft.

I bought my blower in a crate, and assembled it. That shaft comes in one piece, so if a clip was missing, either came that way from the factory, or was lost at dealer somehow.

My only other thought, and it should be obvious during install - did the dealer get the drive shaft to LOCK on the tractor's mid-PTO?!?!

Honestly, I would sooner expect an issue with the driveline between the quick-hitch and the blower itself.....

Either U-joint disintegration or poor install, wasn't asgard's fault.

Good luck!

 

[asgard]

Good news, dealer has called to say the new shaft is with them. They are looking at having it installed by a tech tomorrow.

I am asking them to check over the installation as I am not accepting any liability should it fail again.

I think the second failure is unlikely as it would appear on close inspection that either the retaining clip was missing during manufacture or incorrectly installed and worked itself out in the first hour of use.

Anyway should be in business by the weekend.

Thanks for your replies and words of advice and insight.

 

[RCW]

Good news, dealer has called to say the new shaft is with them. They are looking at having it installed by a tech tomorrow.

Super - glad it's working out!!!

 

[Dave_eng]

Good news, dealer has called to say the new shaft is with
Anyway should be in business by the weekend.

Thanks for your replies and words of advice and insight.

Please let us know after a week or two that all is good because we will all learn from your experience.

Dave M7040

 

[asgard]

Well, I got the new shaft today and will install and run it tomorrow.

No immediate forecast for snow so we will just have to wait for a test under load.

No issue getting a new one, dealer placed a warranty claim against Kubota.

 

[RCW]

Well, I got the new shaft today and will install and run it tomorrow.

Great!!

Check the clips and make sure that sucker locks!!

More I've thought about it, I really do wonder if the dealer was sloppy, and didn't lock the puppy on the tractor PTO. Push it on, hear the click, then pull it back to make sure.....

Less likely that the clip was gone/missing.

Either way is possible, but the important part is you're back in business!!

 

[asgard]

No, the dealer didn't screw up.
The shaft was seated and the collar locked, I rechecked all that and made sure it was fully greased and the chain lubed before I tried it.

The clip is the failure point on this without a doubt. One cap completely missing but the corresponding post unmarked, opposite side sheared. The collar was still locked onto the mid-PTO after the failure, the coupling below it broke.
I have checked all the frame bolts and checked the frame for level and it is all good.
This one is down to manufacturing error.

 

[BAP]

Things like that happen. That's why manufacturers warranty their work to cover mistakes made during the manufacture process. I once had a Chevrolet one ton dump that I bought new and at 900 miles the wheel on one side came close to falling off. Turns out when the dealer took it apart, some had forgot to put the lock ring on the nut for the whee bearings on that side. The nut backed off and the axle was destroyed. GM put a new whole complete axle on that truck because someone had forgot to put on a 99 cent clip.

 

[Craiger265]

Well this happened to me as well, my was a faulty u-joint on a 1 month old new driveshaft I replaced in Dec. Well when it let go, the shaft spun and hit my oil pan, putting a hole in it! After the bang, I looked down and seen the shaft on the ground and the oil. I immediatly shut off the tractor and was shocked at what just happened. I took it to my dealer who fixed everything at no cost to me. They never seen this happen before as well. I have a BX25 with the BX2750