Are CUT Hydro-static Transmissions Reliable?

[airbiscuit]

My theory is that they are. That said, there is still a little trepidation because lawn tractor hydros are not all that robust. By definition, they have to be inexpensive to build, thus not all that robust except for the premium models. I haven't heard about that many reliability issues for CUTs.

What say you?

 

[nybirdman]

Of course they are,can't compare a cheap lawnmower to an HST tractor.
My 22 year old mower ,is still cutting grass($5k when new) in 2004.

 

[Mtsoxfan]

I just sold my NH TC29D, there were no issues with the hydro. Although, there were only 1800 hours on it, not sure where reliability hours are measured from. I don't think hydro trans on any brand are unreliable, the factor to buy or not depends mainly on your intended use.
For what I use it for, hydro was the way to go. Mostly loader work, and flail mowing a couple times per year.

 

[Shawn T. W.]

This was after my last mow of the season on my 2005 Kubota Grand L5030 HSTC ... Still running great!

 

[crazyjake8493]

My current riding mower has a non-serviceable HST and is going on 24 years this season. I feel just fine about the one in my tractor with regular filter and fluid changes.

 

[tacticalturnip]

Absolutely.

 

[4570Man]

The tractor transmissions are built completely different from a lawnmower. HST tractor transmissions are robust and reliable. The biggest percent of the haters don’t even have one.

 

[rScotty]

The tractor transmissions are built completely different from a lawnmower. HST tractor transmissions are robust and reliable. The biggest percent of the haters don’t even have one.

I'm a mechanic & mechanical engineer. I remember when I first looked at the design of a HST I had my doubts about their long term reliability - but they turn out to be very reliable.

I've bought one anyway....partly just out of curiousit.... and have usedit hard for 20 years now. The only repair has been one broken end on a foot-pedal cable @ $20 and half an hour work to put on a new one. The tranny still sounds and works like brand new. I cannot detect any wear at all.

Also, after following this forum for 25 years now it is very rare to hear about a HST transmission giving a problem of any kind. I had my doubts, but the evidence is proving that tractor HSTs are very reliable.
rScotty

 

[Eagle1]

4500+ hours on BX, 2500+ hours on Yazoo Zero turn. Only filter and oil changes, well I did swap the 1996 motor out in the Yazoo, still working as needed.

 

[oldnslo]

Two main killers of any HST is heat and contaminated - dirty oil.

On some CUT’s the only cooling is a plastic fan on the input shaft which are prone to getting broken by sticks getting into them. The cooling fins can also get filled with mud, grass clippings, etc. when oil gets hot it thins out so leaks more which creates more heat which causes more leakage, etc.

Dirty oil wears critical parts causing leakage which leads to above problem of heat.

Properly maintained HST should run 5,000 + hrs before any serious failure.

 

[Eagle1]

True I replace that stupid fan several time before I found the sweet spot for a guard. I have cleaned the fins every time get in there, just not every year

 

[WranglerX]

I have a MF GC1715 with HST and have almost 500 hours on it and I push it hard, its sort of a woose in high range (rabbit) for anything other than flat ground use, but in low range (turtle) is will do most anything if I can keep traction....

 

[GrandpaSmurf825]

Oldnslo hit both the factors that will kill any hydraulic system. Heat and contaminated fluid. About every compact or subcompact utility will have at least a spin on filter and there should be a suction strainer as well. Changing the filter and cleaning the screen at least semi regularly will go a long way towards years of trouble free ownership.

 

[mikester]

If you buy your lawn mowers at a big box store don't expect them to last

 

[Eagle1]

Oldnslo hit both the factors that will kill any hydraulic system. Heat and contaminated fluid. About every compact or subcompact utility will have at least a spin on filter and there should be a suction strainer as well. Changing the filter and cleaning the screen at least semi regularly will go a long way towards years of trouble free ownership.

I will add use the correct fluid, using a heavy UDT in a small machine like my BX does cause problems. Done it in a pinch when a leak took most of the fluid and could tell the difference in heat. Replaced with correct fluid as soon as feasible.

 

[dodge man]

There is probably all sorts of old posts where someone had the hst. All sorts of other problems people have also. For me I like them. I did operate a gear drive for a friend. After reading about them on here I figured it would be like operating a 18 speed on a 18 wheeler. It wasn’t that bad but I was doing tilling so a gear drives strong point.