MX5100

[KYDan]

I purchased an new MX5100 HST, 4WD, with loader from my local dealer August 16th of this year. I love the tractor and the way it performs, but it is so noisy I am forced to wear ear plugs when I use it. There are a couple of concerns that I have about what is producing the noise. The fan is really noisy at higher RPM's as is the turbocharger (2200 +), but these don't really bother me that much. However, the HST is very noisy producing a growl/howl when it is under a load (pulling a hill, or when the loader bucket is full) and at higher RPM's. Is this normal? I know very little about hydraulics and this is my first HST, I had an L2900 prior to this and it had the syncro-shuttle transmission. It was great until I used the HST and it is nothing short of marvelous. That said, the noise issue concerns me as I have suspicions that it might be valve issues within the transmission. Any knowledge that anyone may have about this issue, particularly MX5100 owners/users would be greatly appreciated. This concerns me sufficiently that I am debating purchasing the extended warranty which is quite expensive.

 

[Peacock]

Our MX5100 is quiet. Of course ours is gear though. The only time I notice much noise is when at higher speed in 4wd. I can generally only really hear the turbo at load at around 1500rpm.

 

[bilrus61]

They can be pretty noisy. Did your dealer use Kubota's Super UDT II in the transmission? If not that might be one reason its growling so. At the 50 hour service be sure to use Kubota Super UDT II fluid and see if that makes it run more quiet.

 

[KYDan]

As far as I know he did, I bought my first Kubota from him and found him to be straightforward and reliable. I ran it up and down my driveway today which is a 1,000' gravel drive with one fairly steep incline in it and it did not seem particularly noisy. I drove it up in mid-range then shifted to high range and it made a little more noise in high range. I tried different throttle settings and when I boosted the RPM's the noise dissapated on the climb. I noticed it more the other day when I had been working it cleaning out an old pond on a hot day and the tractor and loader had been in use for about 5-6 hours. Thanks for the reply, this has allayed some of my apprehension. The dealer told me not to worry that they really have no problems with HST and if the did they would take care of it.

 

[nybirdman]

I rarely run my L4240 HSTC in High range(road only) medium range and up and down with the HST+.You do understand the more pedal you give it the higher the "gear",less pedal more power.Took me a while to understand this.:thumbsup:

 

[KYDan]

Yes, thanks. It took me awhile to figure everything out even after reading and having used tractors and equipment for forty years! I love the HST, and even with the noise and my apprehensions I am already declaring this to be the best tractor I have ever had for utility and ease of use. It is a remarkable machine and for loader work the cat's meow.

 

[Grandad4]

We have had 2 Kubota HST tractors for several years now. From what we've seen, a loud HST whine indicates a) it's working very hard or b) there is not enough engine speed, which means less hydraulic flow. If you are accustomed to keeping engine rpm's low as you would on a gear tractor or an older gas tractor, that may be part of what is creating the HST whine. It's not necessary to wind it up all the way, but if you keep your rpm's above 1600-1800, the whine should go away. For loader work, maybe around 2000.

Some people who know diesels say it's better to run them up in the power band anyways.

 

[KYDan]

Thanks for the help. The HST is new to me having moved from the syncro-shuttle on my L2900. I have been deliberately operating at lower RPM's during the breakin period on my MX. Also, in high range on my driveway was where I was really noticing the whine. I have had it above 2200 RPM's sparingly and that maybe some of the issue. It has been performing fine. I am not used to the turbocharger whine either as this is the first tractor I have had with this. My diesel truck is turbocharged, but the sound from it is insulated.

 

[Grandad4]

Appreciate your interest in taking good care of that MX... it's a really nice machine. Break-in puts you in one of those rock vs. hard place dilemmas. Keeping the rpm's low to baby the engine during break-in can mean you're overworking the HST during its break-in; the opposite occurs if you increase the rpm's. Maybe you could take it on a cross-country cruise for about 2 weeks to run up 50 hours of easy operation. :laughing: Seriously, if it were me, I'd try to give the HST a break and work the engine a little harder on the theory Kubota engines are about as close to bullet-proof as you can get.

With ours, for break-in, I kept the rpm's in the mid-range where there was enough hyd flow so the HST, etc. didn't struggle, and varied the rpm. Tried to avoid heavy pulling at first, sometimes we did it anyways. We're at 9 years and 1,000 hrs on one and 6 years and 600 hrs on the other without any downtime or significant repairs. Replaced one air sensor is all the engines needed; engines run as new.

 

[k0ua]

90 percent of my work is done In low range, I use Med. when transporting something and the ground is smooth. you might be able to finish mow in Med. if the ground was nice, High is only for road gear, and flat roads at that. One more thing, it seems my hydro whine got a little quieter after about 50 hours. I dont even notice the whine anymore, uh unless you leave the brake on:laughing:

James K0UA