Why are Hydro transmissions so noisey?

BluRidgDav · Nov 13, 2005

Don't get me wrong, I love the hydro-tranny concept.
But, why are the hydro transmissions on all compact tractors so loud?
The noise of the hydros litterally drowns out the sound of the deisel engines!
This may be a poor comparison, but my hydro-driven Sears garden tractor is whisper-quiet compared to all these "real" tractors. For five times the money, you'd think they could build a quieter hydro!

I'm starting to consider a gear driven 790 or 4110 for the sake of my hearing?!

Thanx, Dave.

Barnboy · Nov 13, 2005

Before the first 50 hrs my B3030 seemed very noisy. After the 50 hr service it has quieted down alot.

CT_Tree_Guy · Nov 13, 2005

Hiya BlueRidge -

I'm curious about which tractor you have that has the noisy hydro. I think it really helps a lot to put as much info as you can into your Personal Information so people can learn more from posts, and help the posters better.

I have a Kubota 5030 hydro and I love the sound of it. It doesn't sound noisy to me, just cool as h*** /forums/images/graemlins/smile.gif It really does seem pretty quiet considering what it's doing. I use Super UDT in it, but I bet it just had regular UDT from the factory, and the tranny has always sounded about the same.

The sound of a hydro is definitely distinctive, no doubt about it.

Cliff_Johns · Nov 13, 2005

If your transmission is loud, there can be several reasons, but the most likely is that you've got the rpm's too low. Hydros scream when they're strained. Try goosing the throttle a bit and it's likely to quiet down.

Otherwise, low fluid or cold fluid can cause the same result.

Cliff

2nstonge · Nov 14, 2005

The hydro 'whine' in my 4110 seemed quite a bit louder during the first 50hrs or so. All that use was in low under a variety of attachments and loads. Now that I'm closing in on 200hrs it's definitely quieter. I do still get it on the rare occasion when I'm in high and really scooting from once place to the next (no load). Tractor is almost a year old.

The dealer did change the tranny fluid and filter at the 50hr service...wondering if that played a part?

-Norm

Kyle_in_Tex · Nov 14, 2005

Shift to a lower gear if possible.

RonR · Nov 14, 2005

The bigger noise in mine reminds me I'm in high range. .........

And Kubota didn't even charge me for that option........

Ron

BluRidgDav · Nov 14, 2005

I'm not talking about a hydro that is louder than "normal".
I'm asking why all hydros are so darn loud?

When I start my Craftsman, I hear the sound of the 20hp gas engine. When I move the hydro lever, the machine simply moves forward or backward, making no "extra" noise, just the constant sound of the engine. When I engage the mower deck, then I get alot more noise, of course.

Now, I'm out test-driving compact tractors, mostly John Deeres. When I start the engine on any of them, there's that rich, deep, deisel rumble. Then I push the hydro pedals, and the WHINING of the transmission nearly drowns out the rumble of the engine! The NH TZ models are the worst.

Maybe you guys are used to it, and it's always been that way, but, to a new-comer, it's really loud. (Maybe after a few hundred hours, my mid-frequency hearing loss will make it all seem to go away, HA-HA)?

My truck's transmission doesn't out-whine the engine.
My Sears mower just moves, it doesn't generate extra whine.
Why do hydro tractor trannys make so much extra noise?

Thanx, Dave.

dicker · Nov 14, 2005

Hi

I have 650 hrs on a 4310 and barely hear the hydro, just the engine.

Richard

hobbyfarm · Nov 14, 2005

</font><font color="blue" class="small">( I'm asking why all hydros are so darn loud? )</font>

BluRidgDav,
It may just be the nature of the beast. That high pressure/highvelocity oil moving around inside the transmission acting on vanes and pistons makes some real noise.

As a veteran of all the early IH hydros (544, 656, Hydro 86, 1066Hydro) none were really loud except the Hydro 100 we demoed once.
We were disking around 10pm close to where the city just
annexed, and the police came and kindly asked us to leave it until morning. There had been three complaints about the noise.
I believe what some of the others mentioned, when you're really working the hydro it gets pretty loud. But, I never notice it except for drawbar work. For PTO work they are kind of quiet.