Rattle

[DitchFisher]

Good afternoon
Unfortunately my 1st post is a mechanical concern. I have a 2004 B7610 with 633 hrs. Yesterday I was walking next to the tractor while my son was driving. I heard a rattle coming from the right rear axle/tire. To me it sounded like a golf ball inside the tire. My son described it as "just like a rattle can of paint". It happened on every other rotation. Today I raised the tractor off the ground and could not replicate the noise, so apparently it has to be under load for it to happen. I would appreciate any opinions before I start tearing things apart. Thanks
Bob

 

[Eric McCarthy]

Does it have one of those bells bolted to the rim that makes a helluva racket when you back up and go forward?

 

[DitchFisher]

That would be nice but no this is definitely a problem sound, I am thinking bearings or worse.

 

[Eric McCarthy]

I would think with only 633 hours it would not be a trashed bearing. I'm stumped on this one...

Have you owned it since new or bought it used?

 

[DitchFisher]

I bought it used last October, but one of the reasons I jumped on this was that the two previous owners kept meticulous records. I was provided with all of the original manuals, dealer invoices, and service/repair records. I have no doubt this was a well cared for machine.

 

[kubotasam]

Check the large bolt that clamps the hub to the rear axle. Check the rear wheel lug nuts for tightness. Check ( especially if the lug nuts are at all loose) the wheel for any cracks.

 

[pmhowe]

It would be good to know whether the rattle is coming from inside the tire or from inside the axle housing. It may very well be that someone left an object inside your tire when mounting it. You didn't say if your tires were loaded.

It is a bit of a job, but you could switch wheels from side to side. If the rattle then moved from one side to the other, it would be a good excuse for a beer and several smiles.

Others probably have better approaches.

 

[Eric McCarthy]

That's kind of where my train of thought was going too Pmhowe something's inside the tire. Stranger things have happened.

 

[hodge]

It would be good to know whether the rattle is coming from inside the tire or from inside the axle housing. It may very well be that someone left an object inside your tire when mounting it. You didn't say if your tires were loaded.

It is a bit of a job, but you could switch wheels from side to side. If the rattle then moved from one side to the other, it would be a good excuse for a beer and several smiles.

Others probably have better approaches.

I don't drink or advocate it, but otherwise, that is an excellent idea! If the sound moves, it is in the tire or involves the rim. Process of elimination is the key.

 

[DitchFisher]

Thanks for all of the advice. The tires are not filled, so I pulled the offending wheel and rolled it around. No obvious cracks and definitely nothing inside. I torqued the hub nut to 100 ft-lbs (per the manual) on both sides. They were not loose but definitely needed tightening. I didn't rotate the wheels, just didn't have the energy, need one of my sons here to help.
Anyway the noise is still there. While driving it I can tell that the sound is definitely coming from the wheel/hub area. Not so much of a worry now I hope.
Thanks again. It is now time for that beer.
Bob

 

[pmhowe]

Hi Ditchdigger,

I don’t think you are home free yet. There is no way I could hand turn a tire fast enough to match the initial loads when the tractor starts off. You may have eliminated the noise coming from the tire, or you may not have.

You’ve said that:
1. The noise comes from the right hand side,
2. That the noise only occurs when it is under load,
3. That it occurs on every other revolution, and
4. It sounds like a paint rattle can.

I would want to enlist the aid of your sons to figure out exactly where the noise is coming from. I’d have your sons walk behind the tractor as you put it under load and have them note where the noise source is. They may not be able to pinpoint it, but they can make a better assessment than you can while you are in the tractor seat. If they can pinpoint it, you will probably know where to go next. If they can’t pinpoint it, but can narrow its location to one side, then I would still switch tire locations and be sure whether the noise comes from axle or wheel. I hope that leads to a good solution. If it doesn’t, it still should move us all closer.

This is an intriguing problem. I look forward to its solution. Please post all the details. Someone smarter than I will come up with a good answer.

Phil

 

[Stumpy]

I'd give the mechanics stethoscope a try here. Get a length of hose, hold one end to your ear and fish around down there (carefully) and listen to where exactly it's coming from. The hose will only allow in sound that aligns with the end making it easier to narrow down the problem location.

It does sound like a bearing, is there any wiggle in the axle on that side when the rear end is off the ground? Make sure it's well supported.

 

[Eric McCarthy]

Another option would be to put the rear up on jack stands and remove the tires and listen then. That will rule out if its something in the wheels or not. Then if you still hear it atleast you can somewhat safely better determine where its coming from...

 

[Bulldog]

If it has those hubs that are suppose to tighten up on the axle I would look hard at them. My old 7100 has been run loose when I got it. Some of the noises that those hubs made sounded like the entire rearend was falling apart. A small amount of movement would make noise in the right situation.

 

[hodge]

Another option would be to put the rear up on jack stands and remove the tires and listen then. That will rule out if its something in the wheels or not. Then if you still hear it atleast you can somewhat safely better determine where its coming from...

He mentioned that in the first post- it wouldn't make noise when raised off the ground. It must be load related, like the hubs or lugnuts.

 

[DitchFisher]

This place is great! I put a stethoscope on it yesterday and heard nothing out of the ordinary. The hubs are the clamp to the axle type. With the wheel on, there is about 1 inch of play (slop) when I push the top of the tire, of course I did not check the hub when I had the wheel off. Both sides do this so I just figured this was normal. The only other tractor I have worked on was an old Fordson, so I have no experience with Kubota.
Bob

 

[hodge]

If you can move the tire/hub on the axle, that is most likely your noise. With weight bearing on it, it can make lots of weird sounds. Maybe you should upgrade to the better hubs- the most common place to find them are on Ebay.
http://www.ebay.com/itm/New-Kubota-...167?pt=LH_DefaultDomain_0&hash=item3ccbd743a7

 

[Stumpy]

1" of slop?!? Meaning you push on the top of the tire and the whole wheel rocks about the axle? Something is wrong, that should be rock solid. Figure out exactly where the play is. If there really is that much play in the axle shaft then the bearings are probably ruined on both sides and I'd closely examine the final drive gears the axles slides into. In fact in such a case it would probably be easier to replace the final drive on each side entirely.

 

[DitchFisher]

It appears that all of the slop is in the hubs. If this is supposed to be rock solid, it isn't. I attached a drawing to show what is happening. The center line of the tire at the top is moving about an inch. (negative camber) Looks like I will be replacing the hubs. Any ideas on what might have caused this? I wouldn't think that this is normal wear and tear. Hodge, thanks for the link.

 

[Apogee]

Ditch,

Before you spend any money, is there some way to tighten the hubs that you've got?

I've often seen them where the tire rocks and I'm not 100% sure that it's unusual. I do know Kubota updated the hub design, so maybe it was to eliminate this issue???

Anyway, I'm suspicious with both sides being the same. Perhaps the locking bolt on the hubs just needs to be tightened to remove the slop (not sure if it works that way but figured I'd toss it out there to get you looking).

I'd also call the dealer and chat with the service manager to find out if the rocking is normal. The hub design is such that there is bound to be some movement because it doesn't clamp tightly to the axle shaft. How much is acceptable is the question.

What does the owner's manual say regarding the hubs? Are they a maintenance point?

Finally, (folks will think I'm nuts and that's okay) if you do learn that some movement is normal, what about pulling off the wheel and adding a bit of grease to the shaft? This will keep the shaft and hub from galling over time and might also solve your noise issue. Worst case, you can always remove the grease later, but at the very least if the noise changes or goes away, you will know you found the source.

Good luck,

Steve