1025R snowblower shaft

My 1025R recently had a failed mid-mount PTO output shaft bearing. I removed the transmission and replaced the bearing and the seal. I am trying to figure out why the bearing failed as quickly as it did (406 hrs total on the tractor).

This video shows the PTO shaft that runs to the snowblower from the mid-mount PTO output, which is under the operator's station. It is clearly whipping around, putting tremendous stress on the PTO output bearing and the snowblower mount bearings (one of which also failed).

Any insight as to why this shaft would be whipping around like this? It does not appear bent. Bad u-joints? The flexing is especially apparent if you go frame-by-frame.

Sorry for the sideways video.

Thanks in advance. Dave
[video play=false:654c4848f0]https://www.yesterdaystractors.com/cvvideos/cvvideo78584.mov[/video:654c4848f0]

Let me know if the video didn't make it. Only displays as audio on my computer, but I can re-download and the video comes back to me, so I don't know what you'll see. Dave

Audio only.
In Modern view and Classic view also.

When shaft is disconnected from the pto output, can you easily turn the blower by turning the shaft by hand?
And can you easily turn the auger by hand with no feeling of excessive drag or any drag/free/drag/free as it all rotates?

Looks like a bent shaft,U joints not in time, there is definitely something wrong in the system.

Any better? I did this one from "modern view," and it says "video uploaded." On mine when I do "preview" the video only shows for a split second.
[video play=false:d7d1e69614]https://forums.yesterdaystractors.com/videos/mvvideo70322.mov[/video:d7d1e69614]

Yes, I can turn the blower by hand no problem. I am thinking it is the shaft u-joints or something bent.

Another attempt
[video play=false:654c4848f0]https://www.yesterdaystractors.com/cvvideos/cvvideo78593.mov[/video:654c4848f0]

Do you know what I mean when I ask are the u joints in phase. IF there is a splined part in that shaft someone may have put it back together out of phase. You ends have to be in time or it will jump up and down like that.

Yes, I do know what you mean by "in time." There is no spline in the shaft; it is continuous--just a welded tube with a u-joint at each end. The u-joints seem to be "in register." The forward u-joint is a "double" u-joint that feeds into shaft which can "telescope" in two special-purpose bearings with hexagonal inner rings.


The forward end of the pro shaft (past the two bearings) is splined. Another u-joint fits on here to connect the snowblower to the forward end of the PTO shaft. I can post a picture of this. Maybe this part is out of time? It is splined, but only goes together one way the way the splines are made. But it could have been damaged. I am the second owner.

A double U joint like that has a spring loaded ball and socket inside that keeps it running true.

Looks like the ball has broken off or the socket is worn or somehow gotten loose.

The picture makes the shaft appear to be bent. If it is, that can beat the ball and socket out.

Sno blower lifts full up without the shaft touching anything on tractor?
Maybe previous owner ran into something with the blower and pushed the blower back or up and caused shaft to bend.

I would remove shaft and roll it on a flat surface like a pool table.
A bent shaft will show up easily.

Steve I think you have it figured out. Something definitely wrong and he should be able to send a bend so maybe you are right.

Thanks. I just went out and laid a 4 foot level along the shaft to serve as a straight-edge. The shaft is straight as far as I can tell. Certainly not bent like it appears in the video. This may sound crazy, but the shaft is actually "working" or flexing as it spins! I have seen other shafts do that, but not in this application.

Could you describe this double-u-joint ball a little more? That would certainly make a lot of sense. I have a spare shaft and will swap it out tomorrow to see if it makes any difference.

Thanks, Dave

Dave,

What Steve is talking about is called a double cardan u-joint.
double cardan u joint

Does the telescope part work? Can you move / slide it by hand? Let us know what it turns out to be, please.

Shaft looks bent . If you keep ruining it like that youll have a lot more problems than you can see right now

jm. Doing some work on this, I am thinking you and Steve are right on. Steve is 100% correct that there is a spring-loaded button inside the double u-joint. Here is a picture of a similar joint from another forum. These are apparently also called Double Cardan joints. I am guessing that spring in there is frozen up or the little ball is not working right. That would explain what the shaft is doing...the shaft is flexing so much because the joint cannot "straighten up" like it is supposed to. I'll get that off of there and post back with what I find.

SV: Thanks. Believe it or not, laying a straightedge (4 foot level) along the shaft, it is straight! The video is actually showing the shaft flexing. I had already disassembled the transmission to replace the mid-mount PTO output shaft front bearing. I do not want to do that job again-two days on my back on a cold concrete floor at this winter's temperatures. As Steve and Pete have mentioned, I am pretty sure it is the "double Cardan Joint" is frozen. I will post back with what I find. Dave

Telescope works. I am thinking it is the double cardan joint.

Thanks. When installing, the "joints" worked, but I think the center button has frozen up. I will post back with what I discover. Dave

You mentioned you are second owner.
Is this your first use with the blower mounted?

No. For the complete backstory, I have used it with the blower mounted for three seasons. When I bought it, I knew "eyes wide open" that the mid-mount PTO seal had a slow leak. I lived with it that way for a few seasons, but this year the seal failed completely, so it forced my hand and I had to repair it.

Upon removing the transmission from the tractor and opening the front cover of the transmission, I was able to access the mid-mount PTO output shaft bearings. The outer of the two was completely destroyed:



Fortunately, the front transmission cover (aluminum) was not damaged so I only had to replace the bearing & seal. I put everything back together, and was able to clear the 10 inches of snow that we got with this most recent storm--but with a lot of vibration. In all fairness, this vibration has always been there as long as I owned the tractor. It bothered me, but the tractor worked, and had snow to clear, so I ignored it.

However, not happy that I had just spent several days on my back on a cold concrete floor working on this, I decided to investigate further. This has revealed that the front snowblower bearings have also failed. Now, when I put the snowblower on back in November, the rear-most of the two special-purpose bearings (the two triangles on the front of the PTO shaft) had failed. I had a spare on hand (having just replaced the same one last year!) and put the tractor to work. We get a lot of snow in my area: 10-12 feet is normal. That new bearing failed in 3 months of use. The front has also failed.

So in short, this tractor is eating bearings. The two triangular ones are not too bad to replace aside from the replacement cost and the down-time, but the mid-mount PTO bearing was a lot of work. It is only February. Last year we had our last heavy snow on May 12, 2020! So I have at least 2 more months of winter ahead of me.

If I have to get out, I can run the snowblower and clear the driveway. It will obviously be putting huge strain on the equipment to do so. So I would rather fix it right. In hindsight, I would have fixed it during the summer. You know--that time of the year when we all have lots of "free time" to work on snow-clearing equipment. Ha-ha.

I hate trial-and-error repairs, but I may have to just buy a whole new PTO shaft. I looked at one of the two I have and it is not easily repairable--JD carries it as one complete part. If this were some antique, I would invest the time in a component-by-component rebuild, but I am guessing that is not feasible here even if it were possible.

There is nothing obviously wrong with either shaft. They are straight as far as I can tell. The "Cardan joint" seems to work as it should. I greased them thoroughly with the Zerks.

I ran it again with just the PTO shaft in place--no snowblower. The vibration is incredible. Something is clearly wrong. (attempting to post another video, this one without the snowblower.)



<video src="https://www.yesterdaystractors.com/cvvideos/cvvideo78799.mov"
controls>http://forums.yesterdaystractors.com/cvvideos/cvvideo78799.mov</video>

SV: I verified the shaft is straight, and the flexing you see may in fact be a "rubber pencil" optical illusion. I even filmed myself wiggling a pencil to be sure, and yes, even frame-by-frame, the pencil looks bent. So I think that is an illusion of the camera. But it still shows how bad the vibration is. Thanks, Dave

Did you run the pto without the shaft installed on it??

Maybe it has a very slight bend or wobble?

Theres definitely a problem at the joint end,that thing is whipping around causing the shaft to flex.The joint is
the problem.

I suspect that the U joints are out of phase. You said that the splines only go together one way, and that is as they should be. But if this shaft has been "remaned" then someone might have welded the spline shaft to the end yoke incorrectly. Check to see if the shaft end U joint at the double cardan joint is in good alignment with the U joint at the other end of the same shaft. A possible mistake would put it 90 deg out of sync. The non movable yokes on both ends of the shaft or tube must be in good alignment. I have seen this kind of error occur. But I have also fought with the double cardan joints on the front driveshaft of my snowplow truck, and I totally misdiagnosed that until I had taken the driveshaft out of the truck.

Good Luck!

Paul in MN

Hopefully you can figure it out . If its a cv joint the end could be broke off and that would cause it to flop like that

Looks like the double cardan / CV joint is toast.

I had one go in a baler shaft and it shook like that until I shut if off.

I'd take that shaft apart and check.

Whats the model number of the blower

I don't think so. Here is a video of the output shaft running alone. My son helped me and sat in the seat, turning on the PTO. I didn't even know when he turned it on, it was that smooth.

Not the best video...me with my hand-help cell phone camera. But the shiny spot on the end of the shaft sits pretty solid, so I am thinking the shaft is running straight.

[video play=false:654c4848f0]https://www.yesterdaystractors.com/cvvideos/cvvideo78878.mov[/video:654c4848f0]

The shaft is a poor design. It is essentially the splined output shaft with a gear on the other end. The gear is supported on either side by ball bearings. But they are really only the thickness of the gear (1/2 in or so) apart. So those two bearings have to support the shaft, and all the weight/vibration it carries. With that little lateral separation between the bearings, the "support reactions" as they are called is incredibly high. I am surprised the aluminum transmission cover itself did not fail.

Thanks, Dave

It is the Deere 54 inch "quick tatch" snowblower. I can't find a model number on it, but it is the current model.
Thanks, Dave

I agree, but I checked the one I have, and it seems solid. I was convinced the internal spring-loaded "button" was bad, but checking the shaft every which way, it seems fine. I can post a video of me wiggling the u-joints by hand if you want. There is no apparent slop in them.

National Weather Service says 7-11 more inches of white stuff on the way. Earlier in the forum there was a debate on the best kind of equipment to move snow. My answer at the bottom of this post.














































RELIABLE!

I should add that the shaft is the "JD" design and the u-joints are welded on. The shaft is OEM, not "reman." The bearings are press-in and not readily replaceable. I got a couple of them out on my spare shaft but only with damage. JD only sells the shaft as a complete $850 part. It is theoretically possible that I could find the proper needle bearings to press in and rebuild the thing but it is also theoretically possible to win the lottery.

Even the parts tech at the JD dealership didn't have good things to say about the shaft. Outside of a custom rebuild at a driveshaft shop, there's no practical way to repair the thing.

Thanks, Dave

U-joints appear in 3 locations on the shaft.
The first is at the back end, right where the quick-connect slips on to the pto output shaft. This is at the lower right of the picture I posted in response to jm.

The second is the "double cardan" joint. This is just behind the hexagonal "telescoping" shaft that slides through the two special-purpose bearings on the snowblower front mount bracket. These are the two triangular housings at the upper left of the shaft in the picture I posted for jm.

The third is on the *other side* of these special-purpose bearings. The end of the hexagonal shaft is splined, and here there is yet another u-joint that slides onto these splines (not shown in the picture).


The most recent test was with the snowblower and this outer-most u-joint removed. Basically just spinning the PTO shaft in its bearings--it vibrates like crazy!

There may very well be problems with the splines and the forwardmost u-joint, but I'm not even there yet!

Thanks, Dave

I agree. Just can't figure out that the exact problem is or how to fix it! Thanks, Dave

Check the female components for a longitudinal crack that might be opening under load or when spinning.

Just a thought.

But it is beginning to look like the problem is down stream of the cardan.

DoubleO7: I took the short end of the PTO shaft apart and found this. The "ball" is worn into an egg shape.


I was able to purchase the u-joint "cross" with bearings at my local part supplier (non-JD) for $20. It is a Weasler 200-0600. I am not experienced with u-joints and CV shafts, but a local old-timer who happened to be in the store said the ball did not look bad. He claimed he had seen them worn almost flat on one side for baler CV PTO shafts and still work fine. Now that I have the "cross," I can put the shaft back together without too much difficulty. Do you think I should re-assemble based on what you see here?
Note: the two "special purpose" bearings have also failed, probably from the shock of vibration. I have one new one installed, the second one is on order as my local store did not carry hexagonal bearings. Part 206KRRB6 It looks fine but has a grind as I turn it.
Thanks, Dave

Note: I surprised myself. My local parts store sold me a Weasler 200-0600 which is supposed to fit based on measurements. Dave

"Do you think I should re-assemble based on what you see here?"

instead of not answering because I don't know, I will say that
I don't know.
But if a new piece was a reasonable price like $100 I would.

Also read these threads:
https://www.greentractortalk.com/threads/1026r-front-mounted-snow-blower-noisey.178910/
And
https://www.greentractortalk.com/threads/1026r-shaft-for-47-or-54-blower.195011/

OK, thanks. I will review those discussions and figure out what to do next. Thanks for sticking with the discussion for so long.
Dave