2015HST Whine

davepays · Mar 3, 2010

I purchased a 2015HST about a year ago now, not my first tractor, but my first HST. Is it normal for it to whine A LOT? It was a cold new england winter day when I tried it out at the dealer, they said it needed to warm up for at least 10 minutes for the hydraulic fluid to reach operating temps.
After putting about 50 hours on it over the summer it still whines when moving anytime the throttle isn't running really high. Sometimes it also whines when I step on the side of the deck to mount the tractor.
Is this just part of running an HST over a gear or is something wrong here? I was reluctant to spend the extra money on the HST, but so far I love it other than the obnoxious whining sound.

Outlander · Mar 3, 2010

Those pumps are dinky and you must keep the rev's up a bit to get sufficient fluid to the various components. The whine is annoying but alas normal. Probably a bit louder in the Winter? Sometimes a fluid change will help a little. That may be a matter of perception though. I went from Hytran to Mystik and it seemed to help? Might have gotten a tad quieter as the tractor got older too? Or did I just adjust?

bp fick · Mar 3, 2010

They whine worse than a spoiled pre-teen.

Warming them up, in the winter, is a pain and takes a long time. Your engine, with 3.5 quarts of oil, let's say, gets up to temp pretty quickly. That HST? Well, it has a couple gallons of freezing cold fluid and that's gonna take awhile. I do not know what came from the factory for fluid, but most people report good results by using a lighter, multi grade, super modern, even semi synthetic or full synthetic type fluid.

If it came with rather old time thick fluid,(and how would you know for sure?) the whine is absolutely worse. Deere, Kubota, and the big oil companies like Texaco-Chevron all make an expensive top of the line fluid. Got nothing to lose by trying an "upgrade" on that fluid, nothing but a few bucks.

manganos · Mar 3, 2010

The whine was like that in my Bota' BX22. I would double check the fluid level and if it is ok let her rip. I haven't heard of too many hydro failures.

LAWALLSTRACTOR · Mar 3, 2010

The whine doesn't hurt a thing, just the nature of the beast and as said before about 1500 rpm's makes it better. The 2516 hst has a higher volume pump on the HST which cuts down on the whine and operates a little smoother, but both are good transmissions.

Outlander · Mar 3, 2010

Any chance the 2516 pump would bolt up to the 2015?

LAWALLSTRACTOR · Mar 4, 2010

Outlander said:
Any chance the 2516 pump would bolt up to the 2015?

No it a wouldn't, and if you did it would probably make more financial sense to trade tractors.

davepays · Mar 4, 2010

Thanks for the peace of mind guys. I'm just over 50 hours and just waiting for some warm weather to do the fluid change and general maintenance so I'll see how an alternative fluid affects the sound. Any specific brands/types to avoid or recommend?

bp fick · Mar 4, 2010

FWIW, go top drawer. That stuff is $65-$100 for 2.5 gallons. It isn't cheap.

Chevron/Texaco Synthetic
Kubota Super UDT (not their standard)
Amzoil Synthetic
I believe Deere, Case, and others also market a top drawer Universal Tractor Hydraulic/Trans fluids as well.

If you are not going to go first class, top drawer, than any house brand at a Farm-Fleet-Tractor Supply will do, (the list is endless) but likely won't be noticeable in performance to what you have now.

No assurance that the horrid whine is going to be abated either way, but you stand a better chance using some super high quality stuff. Clean the screen, if there is one, and change the filter. Those hydro filters are extremely finicky about micron sizing and are not inter-changeable.

Check for any suction leaks, spotting of hydro fluid, and seepage at connections because all these things mean air and air makes these hydros whine even worse.

k54frog · Apr 1, 2010

Dealer has serviced my 2015. It's quite whiny, not a complaint, just an observation. I wear ear plugs whenever I use it, so it isn't so annoying. Currently at 191 hours so it will be back to the dealer fairly soon. My [Craftsman] riding lawn mower w/HST also whines, but is still going after 7 years of abuse.