Wheel broke off !

[Post Carbon]

Hello Gentlemen,

So I just finished tilling up my potato patch, went to park the Kubota 7800 and felt a bump. Got off and the front left tire has fallen off ! Broken off. WHAT ON EARTH HAPPENED?

I'm a new owner of this used tractor and have little experience with maintenance, certainly with wheels falling off of anything. Feeling stunned. What does this mean? I have no idea. How does this kind of thing happen? Have I wrecked the axle? Will I have to take this to the doctor? Can I buy a part to fix it? It looks serious. I'm pretty sure this is much more than a tire problem.

Enclosing photos to help with diagnosis. Really glad it didn't happen in the middle of the field.

 

[nfowler]

Go to the Kubota Owning/Operating forum and do a search on "Broken Front Wheel".

Here are two relevant threads in particular that you'll find.

http://www.tractorbynet.com/forums/kubota-owning-operating/214500-b2910-front-wheel-snapped-off.html

http://www.tractorbynet.com/forums/kubota-owning-operating/149881-b7800-busted-axle-441-hours.html

Good luck,

N. Fowler

 

[Post Carbon]

N. Fowler, many thanks for the redirect ! I'm not completely cognizant of all the subtleties of this site yet, but have received much help and advice so far ! Really bummed out by this development, but I will soldier on !

PCP

 

[dex3361]

Do you have a FEL? Are your front tire loaded with fluid? Looks like the weld broke. Though I cant see details close enough. If it is a broken weld you may be able to disassemble it and either re-weld it yourself or have it re-welded.:thumbsup:

 

[Post Carbon]

Yes, I do have a FEL, and tires are loaded. I will have to take the tire off, obviously, to really get a gander at what's up. But I would think that something like this would take a lot of stress--would a weld really hold up well? Freaks me out. Makes me think I should take the opposite wheel off too, just to see how it's doing.

 

[kevinj]

Yes, I do have a FEL, and tires are loaded. I will have to take the tire off, obviously, to really get a gander at what's up. But I would think that something like this would take a lot of stress--would a weld really hold up well? Freaks me out. Makes me think I should take the opposite wheel off too, just to see how it's doing.

No reason to remove the tire. Separate the rim and hub, open the gear case and pull out the stub axle.

It will take longer to clean the thing up than make the repair.

 

[dex3361]

Yes, I do have a FEL, and tires are loaded. I will have to take the tire off, obviously, to really get a gander at what's up. But I would think that something like this would take a lot of stress--would a weld really hold up well? Freaks me out. Makes me think I should take the opposite wheel off too, just to see how it's doing.

The reason I asked about the front tires being loaded is when the front tires are loaded it doesn't allow enough air space to give the proper dampening. I have even seen the wheel center brake out. For this reason I would leave the fronts empty of liquid ballast. :thumbsup:

 

[Ductape]

I'm with KevinJ..... looks bad, but not a major repair. Kubota must have had a batch of bad axles, because there was another member with the same problem within the past couple weeks. I'd ask your dealer if Kubota is offering any help with these, since they seem to be having a problem. Use the search function and print off several treads where people have had the axle break and bring them in to the dealer.

 

[Creamer]

Dex3361 - I agree front tires do not need to be loaded when you run an FEL. not enough spring in the tire to protect the structure.

From the photos is looks like this may have been cracked for a while. There is no reason you cannot get the hub and stub shaft out and have them welded and they would be as good or better than new. Of course it takes a welder that knows what they are doing but I would not hesitate to repair it that way.

I may want to check the other wheel though to see if it is cracked. sometimes cracks are hard to see but if you wash it off and dry it with a hair dryer the water in the crack will show up after the surface is dry displaying a crack that cannot be seen by the naked eye. There re more professional methods such as a die penetrant, magnetic resonance, etc. but this is quick and easy for us tractor guys.

 

[s219]

Yeah, that's clearly been a fracture in progress for a long time based on the rust on part of the crack. So if it's any consolation, you didn't cause the problem, you're just the poor sucker operating the tractor when it was finished off!

 

[brain55]

Do yourself a favor and replace it with the axle from a B21. You will have to buy new studs too because they have screw-in studs rather than press-in. They are much stronger than the B7800 axles. I was responsible for a fleet of these machines all with foam filled front tires, when they broke I would replace them with the B21 axles and never have another problem. I was working for a landscape contractor and believe when I say these machines were abused.

Brian

 

[crazyal]

I would also look at the other axle to see if it's showing signs of cracks.

 

[Post Carbon]

Do yourself a favor and replace it with the axle from a B21. You will have to buy new studs too because they have screw-in studs rather than press-in. They are much stronger than the B7800 axles.

Hey, Brian, thanks for the idea. I would definitely want something good and strong if I'm going to put the work into this.

I'm looking at the parts list for both the B21 and the B7800, from the Messick's site. According to their parts list, the part number is exactly the same for both the B21 and the B7800. So is that a Messick's thing, that the parts would be exactly the same? Same part number, same price, everything.

How did you find that your parts for the B21 were stronger? I would like that to be the case, because I would definitely like to go that direction.

Thanks again.

PCP

 

[Post Carbon]

Well, it's over a year later, but I wanted to post the photos of my repair, since the thread that helped me most (http://www.tractorbynet.com/forums/kubota-owning-operating/214500-b2910-front-wheel-snapped-off.html) was so great with the pictures, and I figure one more example of a repair is always helpful.

I'll probably post in a couple different posts, as there are a lot of photos. I'm doing an B7800 axle repair for dummies here.....

OK, this is a bit awkward, and let's hope the thumbnails stay in order.

1) the broken part(s) and the new hub, shown without studs in yet
2) cleaning the old sealant off--why not do it in the comfort of a warm kitchen
3) outer plate
4) hub seated through plate
5) seating the C rings--the guy at the tractor place said to put them in with lots of grease, like gluing them in so they stick tight
6) seating the gear (yeah, getting that off originally was tough--used a 3 prong gear puller)
7) placing the bearing
8) seating the bearing, tiny taps
9) oh, go to the next post

 

[Post Carbon]

To continue B7800 Axle Repair for Dummies:

1) Everything back, hopefully, in place, ready to re-attach
2) Waiting tractor, great place to break down, couldn't have planned that one better
3) Uncovered
4) Close up
5) Applying the sealant into groove--I don't get manicures
6) Almost completely attached. Will fill with about a gallon of oil after this....
7) Tractor, back in service !!

 

[texasjohn]

great update and photos...great job!

 

[Gordon Gould]

Pictures are the greatest - Thanks.

 

[Guesseral]

It looks like that old one had already been welded before you got it? Did it take this long to get the parts or just this long to get it posted?

 

[Post Carbon]

It took only about a week to get the part--the photos are from last year and they've been hanging around awhile. And it's possible it had previously been welded, yes, but I'm the 2nd owner.

 

[riptides]

You know your a true B7800 owner when you do this repair!

Nice pics!