Kubota MX5100 Gear Whine

   / Kubota MX5100 Gear Whine #1  

kf75

New member
Joined
Sep 5, 2012
Messages
2
Location
Near Montreal, Quebec, Canada
Tractor
Kubota MX5100DT, Ford 8N 1947
In July 2012 I bought a new Kubota MX5100DT tractor, manual transmission, no cab, with 844 loader. This tractor replaces my 1947 Ford 8N that I have used for the last 33 years. I have used the Kubota about 25 hours, mainly to cut my fields with a sickle mower.
So far I find the Kubota an excellent tractor, except in one respect. The transmission gear whine is very noisy, to the extent that during my hay cutting I had to put cotton in my ears, and wear ear protectors. I could still hear the whine. I used engine speed of 1500-1800 rpm, and cut in 4th gear, low range. First gear high range was more noisy. Any gear whine of my old 8N is negligible compared to the new Kubota.
My question is---is this whine normal for this Kubota model, and if it is, is there a type of transmission oil that would help to quiet it? I believe it was delivered with Kubota UDT oil, although I'm not sure. Would changing the oil to super UDT or Super UDT synthetic help? Any comments on this would be most greatly appreciated. I have not yet contacted my dealer about this, as I prefer to see what comments I receive from this forum.
 
   / Kubota MX5100 Gear Whine #2  
I'd be comparing the noise to another MX5100. Everyone has different tolerence to noises and it does make a difference to the operator and some tractors are more offensive.
 
   / Kubota MX5100 Gear Whine #3  
Cant speak to a specific gear whine as mine is hst ....but I believe it is considerabley louder than my old MF 35 gas or my Ford 600. You should be running a higher engine rpm to achieve closer to 540 pto speed. That has taken some adjustment on my part as I ran my old iron @ 1500-1600 rpm for all pto applications My new Kubota needs 2500 rpm for 540 pto speed.
 
   / Kubota MX5100 Gear Whine #4  
i can't hear any gear whine over the engine at any rpm with my 20 year old jd1070 with 2600 hrs. Maybe because it is broken in, but I doubt it. Has the noise gotten any better or worse in those 25 hrs? If it has gotten better I would say maybe it's break in, but my guess would be that there is something wrong. I would take it to the dealer or if that isn't practical they should come to you to at least listen to it. 2 months old with 25 hours They owe you that much I think, and if there is an issue that is what warranties are for. This should be a good test of your dealer.
 
   / Kubota MX5100 Gear Whine #5  
Mine does the same. Worse in 4wd. Worse in high range. Worse under a load. As far as I know it's a result of the spur gears that kubota uses in the final drives.
 
   / Kubota MX5100 Gear Whine #6  
i agree with bucktaker i run the pto at 3k anything less will stall the tractor as far as gear whined my 7040 its loud but its liveable it may be the tranny they use in the 5100 did you ask the dealer what could be the problem i hope you get it sorted out happy baleing
 
   / Kubota MX5100 Gear Whine #7  
I have the MX 5100 HST 4WD, therefore, it is an apple to oranges analogy, but it is very noisy. HST and turbo whines in my case. I do wear ear protection. That said, it is by far my favorite small tractor that I have ever owned over a forty year period. If you have questions contact your dealer and have him come to your place and listen to it.
 
   / Kubota MX5100 Gear Whine
  • Thread Starter
#8  
I thank everyone for their replies. They have all been most helpful. I will ask my dealer to come over and listen to the tractor, but judging from the replies on this post I’m pretty sure the gear noise is normal.
Since my original post I have used the tractor for jobs requiring less time. I have not used ear protectors as I found the gear noise less bothersome. A lot of this work was in the woods, where I was concentrating more on not hitting the trees with the loader. I'm thinking my hay cutting in the summer was extreme noise exposure, as the tractor was in uninterrupted use for 5-6 hours straight each day, for 5 days, with the loading from the mower varying all over the place due to my uneven fields.
I agree with the advice that I should be running my PTO at the rated speed (2700 rpm). This would allow me to cut my hay faster. I used lower rpms because the Kubota Operator’s Manual specified the tractor has to be “broken-in” for the first 50 hours, and specified to not to operate the tractor at full speed for this period.
Again, thank you for your replies.
 
   / Kubota MX5100 Gear Whine #9  
I have the MX5100 (Gear) with 200 hours. It still has the whine, bt not as bad as it was. I, too, upgraded from an 8N. It's quite an upgrade. I talked to my dealer about the gear whine and he told me that it is the "luck of the draw" when it comes to noisy gears. I wish I would have driven all the 5100s he had on the lot and hand picked the one they delivered to me, but I was not aware of the whine issue.

Let me know if different lubricant makes a difference.
 
   / Kubota MX5100 Gear Whine #10  
I have the MX5100 (Gear) with 200 hours. It still has the whine, bt not as bad as it was. I, too, upgraded from an 8N. It's quite an upgrade. I talked to my dealer about the gear whine and he told me that it is the "luck of the draw" when it comes to noisy gears. I wish I would have driven all the 5100s he had on the lot and hand picked the one they delivered to me, but I was not aware of the whine issue.

Let me know if different lubricant makes a difference.
 
 
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