Grinding Sound !! - Dealer Says NORMAL

[Doc_Bob]

Long story - sorry

I must say you are doing a great job and you are being very patient. All of this is a great lesson for the rest of us, should we some day be in the same situation.
Bob

 

[PineRidge]

Dusty is right.
Bob

Dusty is always right.

 

[jinman]

Update - Summarized. NH rep visited. The tractor's lift systems (3PH and FEL) made a terrible whining noise, upon start-up, with him and a service tech feeling under it, etc., and while he was operating it. He experienced the grinding noise, 1-2 min. after he started driving the tractor. Two short grinds, then one longer one. He operated the tractor for 30-45 min. It did not make the noise again. (This follows a pattern previously noticed and captured on tape. If it makes a lift noise and lifts slowly, the grinding noise will occur shortly afterward. If the lifts operate ok at start up, then the grinding noise will occur after an extended period of operation.)

NH rep wants to change to a cold weather fluid. He indicated he didn't hear the noise on the tape, which I have now shown to several people, all of which have no problem hearing the noise. I don't know why thinking a cold weather fluid will cure the problem. It started making the noise in July in NC, in 90-95 degree weather.
.

The more I hear about this problem, the more I am convinced the problem is not in you hydro transmission or main hydraulic pump, although it may shortly become a problem in both if you don't find the problem soon. The only thing that is common between the main system and the transmission is the supply of fluid: reservoir, plumbing to the main filter, and the filter itself. I believe you either have a restriction in the supply or air getting into the lines at a leaking connection. Since your fluid doesn't foam, it doesn't really sound like air leaking into the suction side of the pumps.

Are you willing to invest in a 3000-5000 psi pressure gage and fittings to go to a quick connect like the ones going to your loader (probably $35-$50)? If you build a pressure test rig, then you can put it on one of the FEL quick connects and check system pressure. If you can't get 2500 psi when you operate the joystick or if the pressure is erratic, you will have show the actual pulsating problem that is causing your noise. A video of the gage would also make nice "evidence" if you needed it.

The reason for changing your main hydraulic reservoir fluid and filter was to ensure the filter did not have restriction and that the original fluid did not have trash clogging a pump inlet. It wasn't changed due to normal wear and tear, but as a troubleshooting technique (easter egging) to eliminate those as possible problems. I think you have to be fairly confident that your fluid is clean and your filter is flowing freely, but the intermittent nature of your problems makes me think that a "chunk of junk" too big to flow out during the oil change, might be blocking your reservoir outlet to the filter. Of course, I am just guessing. The only way to be sure is to completely disassemble the plumbing and inspect it for restrictions. If it's in the reservoir...well, that means a major disassembly and inspection.

The NH rep has to be given a little patience. In the corporate world of today, every penny is pinched 'til Abe screams for mercy. The NH rep is going to have to try every low-cost approach he can come up with. If he jumps from a field test drive to replacing a tractor, he won't be employed by NH for very long. It will be a long, tedious process of testing , trying, and justifying. In the end, you will be fighting an uphill battle that won't do anything to build your confidence in your tractor. I just hope it's a small hill and a short battle. You deserve a better product.

 

[IH3444]

If they do replace your fluid with a "winter" fliud, get the details about the fluid if possible. Full synthetic fluids are good for all year round, and usuall offer additional protection against summer heat.

 

[whitetiger]

Check the fluid level in your sensi-trac gearbox. I have found two of these units where a bearing race would spin in the housing and emit a horrid screetching noise for a couple seconds, usually when oil was cold. The way I found the first one was but putting the tractor on 4 jack stands and running it. The noise sounded like it was coming from further back untill I could sit next to it with it running and it screetched.

 

[Dusty]

Check the fluid level in your sensi-trac gearbox. I have found two of these units where a bearing race would spin in the housing and emit a horrid screetching noise for a couple seconds, usually when oil was cold. The way I found the first one was but putting the tractor on 4 jack stands and running it. The noise sounded like it was coming from further back untill I could sit next to it with it running and it screetched.

When the race spun in the bore, did it ruin the case, or were you able to press another race in? My worry would be that if it spun once, then it might not hold the new race any better. I know that they make a Loctite product to remedy this problem, but don't know how well it works in the long run.
Dusty

 

[Birdman253]

Every day that you don't have the tractor and it is in there care and custody for a warranty repair adds days to the warranty at the end.
Dusty

What gave you that idea?

 

[Soundguy]

Considering the 3pt lift uses only a few ounces of oil, and the lift cyl may actually leak air ( and some oil ) pretty good.. air entrainment cavitation in the 3pt lift should 'settle' out real fast.. vs air entrainment int he HST drive system which is what i would worry about much more.. ( though if there is cavitation.. the pump will soon detonate.. or at least suffer for it.. )

I've been reading this thread.. and so far.. cavitation has been the only 'big' issue that has come to my mind.. cavitation can make a decent 'roar, very different than a squealing valve or relief.. etc..

Not saying that is what you have got.. but so far it's on the top of my list of suspects... that or a bearing that is growling..

Soundguy

Soundguy, The NH rep looked at the dipstick for the hyd system after running it for a while. He saw only minimal (~1-2 bubbles) on the stick. He ruled out cavitation in the system. He also said that cavitation would cause the lifts to be "spongy". I didn't know what his def of spongy was, but the slow reactions to control seemed spongy to me. I took it to mean that he was not seeing spongy. Or, maybe that he didn't see spongy like he didn't hear the noise on my tape.

I have suspected cavitation from the beginning. When they changed the fluid at the warranty visit, and didn't see metal fillings in the fluid or filter, I assumed it was cavitation, but with the experts continue to say no. I don't know the fix on a cavitation issue, but it is being discounted for whatever reason. (I know that changing hyd fluid is not cheap.) If changing to the lower temp hyd fluid "fixes" it (eliminates the grinding noise and the lifts work as designed) fine, but if there are future problems with the hyd system or HST, I want them to be covered by the warranty...essentially forever. If they can't guarantee that, I'd prefer to have the tractor replaced.

Shvl-the changing fluids idea came from the dealer. I was told by several people at the dealer to make sure I changed all the fluid on the tractor at 50 hours. I realize the owner's manual says differently, but was told to do so more than once, so I thought it was common practice (evidently is for Kubota?). According to them, it is to get out the break-in oils. It's supposed to cost ~$350, according to "them". I was going to do it. After complaining about the extended time they kept it at their shop, I mentioned that it looked like they should offer to make a payment, change my fluids, give me an ink pen, or something, in compensation. They offered to change my fluids, and I thought it meant the whole $350 worth. When the dealer took the tractor it had 22.4 hours on it, so I figured the break-in fluids could be changed and I'd be happy and we'd all move on. But the grinding noise persists, and the lift issues have arisen since it was in their shop. And I'm not too happy. They changed the engine oil and filter, after changing the hyd fluid and filter. I mentioned this to the NH rep and he said all that was left to change was the power steerng fluid and the front axle oil. I told him that I had expected all flluids to be changed, as advised by the dealer. A minor issue, but just another example of how this is going.

 

[Soundguy]

When the race spun in the bore, did it ruin the case, or were you able to press another race in? My worry would be that if it spun once, then it might not hold the new race any better. I know that they make a Loctite product to remedy this problem, but don't know how well it works in the long run.
Dusty

Depending on the location, I've been able to 'peen' or 'stake' in new races that have spun.. all depends on the housing metal.. and the amount of clearance.

Overboring and bushing is another option..

Depending on how replaceable the part is.. I've even gone as far as weld and re-bore.. or braze and rebore to bring a housing back in tolerance to hold a pressed in part.. again.. it really depends on the application though..

Or.. just plain replacement if ti is an easy/cheap bolt on part..

Soundguy

 

[BobRip]

At this point it seems reasonable to me that you should have a loaner free of charge until they fix the problem. This does two things: One you have a tractor to use. You paid for one, you should have one.
Two: If means they are the one suffering financially by having two tractors tied up in this process and are more likely to take the necessary actions to fix your original problem. I can't see why they would not feel obligated to do this. They may not offer it, but you should definately demand it. I think there is such a thing as too much patience. Don't get me wrong, you have done a fine job of managing this. I just have not heard a push to get a loaner. At present you are doing all of the work and suffering. Make them share the suffering. Even if the loaner is used, they will still have thousands of dollars tied up and that transfers the pressure to them.