Buying Advice Done with hydrostatics

[daugen]

I believe there is a big difference between part throttle on an air cooled gas engine and part throttle on a liquid cooled diesel.
On hot days those gas engines need all the air they can get to stay cool apparently and the benefits of more air seem to outweigh
higher fuel usage and wear/tear on machinery. I think this is also because during warranty period manufacturers don't want to pay for cooked engines due to clogged fins and coolers so they engineer the air flow for worst case, maybe the cooler being half plugged shut.

I don't see hydro trannies getting that dirty, so it's just air flow, almost all the zturns have fans on top of their hydro units.
So clearly heat is an issue for them. Lower rpms means those fans are running at lower speeds, I can see the need.
The hydro trans on my ancient Cub Cadet is a work of art, neat looking finned aluminum case, looks like Buck Rogers could fly it to the Moon...

 

[HEC]

Hydro Gear makes about 5 levels of HST rear transmissions. The lowest end Cub Cadets use the lowest grade hydro, just like everyone else. About 4 grand you get their next to best trans, and the top tier Hydro Gear commercial units are in the 7 grand range. Usually better motors/trans as you go up in American dollars... [ Cub Cadet wise ] Hydro Gear used pressed powder gears in their first two grades of trans, with actual machined metal gears higher up.

Thanks Jerryk that sure is good to know as I may need a new mower soon . I have an old toro wheel horse hydro that is over 20 years old and still going , it seems to have slowed down a bit , and I do change the oil in that tranny quite often .

 

[IH3444]

My understanding is WOT is to reduce the stress to the charge pump, and main pump for the hydrostatic transmission. The pistons? in the charge pump like to take many more small bites of fluid than larger bites at lower rpm.
I read about this years ago, and haven't been able to find the article.

Also found this, looks like low viscosity JD fluid is about at 5w oil.
Viscosity Charts - Bob is the Oil Guy

 

[cdaigle430]

The hydrostatic tranny on my 2009 cub-cadet with only 300 hours is kaput. This was my second hydrostatic mower, the previous one was a Toro that lasted much longer but it still went too just before I bought this one. No more.

Anybody know off-hand the last year the the ford riding mowers had classic manual transmissions? I'll be looking for a 54" or bigger deck. Or maybe there are current models with standards?

TIA

I have a 2006 Husqvarna with 400 hours on it (YTH2448) paid 1700 for it, runs great and 0 problems, have 2 acres to mow and have no complaints about the transmission. I always mow WOT and make sure the fan over the transmission is clean-also mow on a 30 degree slope. When it goes I will buy a 54 inch deck for my MF....

 

[4570Man]

I mow at WOT. My grasshopper has 2200 hours on the hydraulics. I doubt very many lower end gear mowers would even make it that far.

 

[ruffdog]

I still have my 1983 Cub Cadet 982 hydro garden tractor. It got a new engine 20 years ago but has been very dependable.

 

[fitterski]

Wide open throttle

Thanks, I learn something every day. Never heard that one before, knew about full-throttle, firewalling it, balls-to-the-wall but not WOT. That's what I've been using. This CC has been cursed since the day I got it. The deck height cable pulleys were made of plastic and every time the deck took a bounce the cable would jump off, eventually cutting the pulleys. I had my blacksmith make new ones from steel and they've been working like a charm ever since. The deck belt pulley idler was totally cannibalised and almost seized due to wrong assembly, it cost me 5 belts the first two seasons, the dealer couldn't find the problem. I finally did, belts have been lasting two seasons since.

 

[daugen]

WOT is your engine at the highest throttle setting, under load.
I believe High Idle is the engine at full power, NOT under load. Usually get 200-300 more rpm?

for most engines, and my experience is in diesel, you need to hit rated WOT under load or the engine is either overloaded,
air starved, something not adjusted correctly, and basically if you can't hit spec'd WOT, you have a problem you need to fix.
Then once you know your engines will hit WOT under load (my experience was in Detroit 8V71TI's which absolutely had to reach 2300rpm under load)
you ran at 80 to 90 percent of load. But never flat out, or WOT.

I keep forgetting to do this, but my Kubota F mower runs at 3050 WOT, with mower deck on. I want to see what it will do with mower off. That would be
High Idle, if I have this right. I mow at 2600rpm btw. Once upon a time fast speeds like that would have blown diesels sky high, now that's slow for the Asian diesels.

I keep coming back to the WHY on this. Most of our manuals say run flat out. I never do. Every machine is air blasted when done and radiators/coolers always clean before I start.
I'm just surprised hydrostatics aren't designed to work perfectly over a certain rpm, like 300 rpm over idle. Clearly they are not.
Can someone explain in a little more detail why?

My feeling is these hydrostatics should last many thousands of hours without anything other than oil changes. If they are breaking too soon, sure would be nice to know what is
causing that. Tuff Torque isn't going to tell you...they are selling replacement parts nicely I'm sure.

Can someone explain mechanically why it is easier on hydrostatics to run at full rpm? I understand the basics but what actually is stressed
when you don't have sufficient pump pressure? I thought that was when things stalled...not broke.

 

[fitterski]

WOT is your engine at the highest throttle setting, under load.
I believe High Idle is the engine at full power, NOT under load. Usually get 200-300 more rpm?

for most engines, and my experience is in diesel, you need to hit rated WOT under load or the engine is either overloaded,
air starved, something not adjusted correctly, and basically if you can't hit spec'd WOT, you have a problem you need to fix.
Then once you know your engines will hit WOT under load (my experience was in Detroit 8V71TI's which absolutely had to reach 2300rpm under load)
you ran at 80 to 90 percent of load. But never flat out, or WOT.

I keep forgetting to do this, but my Kubota F mower runs at 3050 WOT, with mower deck on. I want to see what it will do with mower off. That would be
High Idle, if I have this right. I mow at 2600rpm btw. Once upon a time fast speeds like that would have blown diesels sky high, now that's slow for the Asian diesels.

I keep coming back to the WHY on this. Most of our manuals say run flat out. I never do. Every machine is air blasted when done and radiators/coolers always clean before I start.
I'm just surprised hydrostatics aren't designed to work perfectly over a certain rpm, like 300 rpm over idle. Clearly they are not.
Can someone explain in a little more detail why?

My feeling is these hydrostatics should last many thousands of hours without anything other than oil changes. If they are breaking too soon, sure would be nice to know what is
causing that. Tuff Torque isn't going to tell you...they are selling replacement parts nicely I'm sure.

Can someone explain mechanically why it is easier on hydrostatics to run at full rpm? I understand the basics but what actually is stressed
when you don't have sufficient pump pressure? I thought that was when things stalled...not broke.

Ok, there's maybe a misnomer in there then i.e. if WOT is wide open throttle then that is a throttle valve position and not an rpm as online definitions that I have found would seem to confirm. In a word: maximum duct breathing. What it might _mean_ though in practice is limit rpm MAINTAINED under design limit load by let's say the governor. THAT, were it to ever happen after a month's use, would mean an engine that is still like new. I'm thinking of the stall-rpm on a big rig, as an indication of engine condition although more than just the engine comes into play.

Back to these HST's, at least part of the problem, according to gossip cause I'm anything but an authority on them, is a lack of cooling or inadequate cooling. I cannot state this as I simply don't know, but IF that's what it is then another pound of aluminum fins and another quart of oil should've been designed-in. According to my dealer the pumpmotors are computer machined to very close tolerances and wear can too easily go out of tolerance for more than just one reason.

Bottom line from my side of the equation is that I don't CARE about the cause, the nitty-gritty, or the whatever rationale, I do not consider 300-hour life as being normal except for biodegradable garbage-bags.

 

[buickanddeere]

As others have said . WOT for cooling . WOT with the forward travel pedal half way down is less stressful to the transaxle vs 1/2 rpms and forward pedal all the way down.

 

[fitterski]

As others have said . WOT for cooling . WOT with the forward travel pedal half way down is less stressful to the transaxle vs 1/2 rpms and forward pedal all the way down.

and as I have said what I i have been doing all this time is lock throttle to full AND push with travel pedal full down AS WELL until either the job gets done

 

[daugen]

As others have said . WOT for cooling . WOT with the forward travel pedal half way down is less stressful to the transaxle vs 1/2 rpms and forward pedal all the way down.

this is the WHY....can you explain this. What could stress the transaxle more than torque or shock loads, and if the rpm is down, power is down, so ???
Cooling is easy to understand unless part throttle and heavy load is causing excessive heat to trans.

 

[fitterski]

I knew I was getting junk when I purchased it. The problem was I could not afford the step above junk at the time. My plan is to abuse the junk for the span of the 3 year wanranty and hopefully get a new tranny near the end of it. When it goes out while not covered by waranty, my plan is to replace it with a better one, like a K66 or a K72 or a complete machine a step or two better.

My previous mower was a prehistoric small Toro that I got for free, I ran it into the ground but that took me another 4 years after the previous owner decided to dispose and get a new one after 8. Last week my son came over to do my lawn in 6 hours with another beat-up El-Cheapo 38" Simplicity with something like 1400 hours on it. My hunch is that the issue is a *not precisely controllable* planned obsolescence one filtered at the QC level. You could get lucky and end up with a low-end product that far outlasts the Ltd's.

 

[fitterski]

I've read all the responses but am still in the dark about the exact problem. I've spent my life in technology at various levels and am not one of those who merrily abuse everything they start up. In addition my farm on the northeast coast NEVER sees temperatures above 25c, the field is mostly level and the grass seldom above a few inches, the transaxle is clean, always full of clean specificatiion oil, the machine was 'professionally' (?) serviced every spring.

When I parked it last fall it may have been below spec performance but I certainly didn't notice anything. I never noticed any slowness in all these years. The dealer asked me if there was any oil where it had been parked, the was none. All I saw was on the left axle in the form of definitely LIGHT oil sweat. The axle, as always is full of clean spec oil. The dealer also had me go through some hoops to 'recharge' the pump, all to no avail. Hydro-Gear asked him to open the unit and report to them, he said he'd be happy to do so at $80/hr, his going rate. They said they'd get back to him and that was almost a week ago.

So my first question was and remains: how can the performance go from acceptable to useless in 6 months of doing NOTHING? I can barely resist the urge to take it apart myself (meticulously under the loop) but my lawyer advises to have that done and documented by unrelated pros for possible future use. I know lawyers hardly ever advise against moving but he agrees with me that 300 hour life, entirely REGARDLESS of any rationale or figure-skating bravado, is acceptable only from biodegradable garbage bags. An overlord legal warranty here (civil code) says that a product must satisfy 'reasonable expectations' so all would hang on what a judge deems a reasonable service life.

That's where it's at at this point in time.

 

[GirlWhoWantsTractor]

My previous mower was a prehistoric small Toro that I got for free, I ran it into the ground but that took me another 4 years after the previous owner decided to dispose and get a new one after 8. Last week my son came over to do my lawn in 6 hours with another beat-up El-Cheapo 38" Simplicity with something like 1400 hours on it. My hunch is that the issue is a *not precisely controllable* planned obsolescence one filtered at the QC level. You could get lucky and end up with a low-end product that far outlasts the Ltd's.

My old Husqv came with the property 5 yrs ago, beat up and high hours, so I decided to use it for all the rough stuff and run it 'til it dies. It refuses to die.

The NEW Husqv on the other hand......not so much.

 

[GirlWhoWantsTractor]

So my first question was and remains: how can the performance go from acceptable to useless in 6 months of doing NOTHING? I can barely resist the urge to take it apart myself (meticulously under the loop) but my lawyer advises to have that done and documented by unrelated pros for possible future use. I know lawyers hardly ever advise against moving but he agrees with me that 300 hour life, entirely REGARDLESS of any rationale or figure-skating bravado, is acceptable only from biodegradable garbage bags. An overlord legal warranty here (civil code) says that a product must satisfy 'reasonable expectations' so all would hang on what a judge deems a reasonable service life.

That's where it's at at this point in time.

After my suite of brand new higher-end kitchen appliances (all different brands) each failed shortly after their crappy 1 or 2 year warranties expired due to known issues, I have to suspect we're looking at a new business model that includes planned early failure/obsolescence. They disguise this with frequent changes in brands/models and justify it by the constant introduction of mostly useless new features, gimmicks, and styles. Did you know "stainless steel appliances are now OUT"?

Good luck with your suit. Stick it to them. We probably can't force them to make better stuff, but how about a little more honesty about expected service life? Although a lawyer for the other side could argue they ARE being honest, by offering such short, cruddy warranties.

 

[LD1]

So my first question was and remains: how can the performance go from acceptable to useless in 6 months of doing NOTHING? I can barely resist the urge to take it apart myself (meticulously under the loop) but my lawyer advises to have that done and documented by unrelated pros for possible future use. I know lawyers hardly ever advise against moving but he agrees with me that 300 hour life, entirely REGARDLESS of any rationale or figure-skating bravado, is acceptable only from biodegradable garbage bags. An overlord legal warranty here (civil code) says that a product must satisfy 'reasonable expectations' so all would hang on what a judge deems a reasonable service life.

That's where it's at at this point in time.

The issue you are going to have is NOT the 300hr life.....

Its the 9 YEAR life. And IMO, most judges/jurys would find that to be perfectly acceptable for a lower end model.

I mean, what about things like kitchen blenders or a microwave? Get 10 years out of one and thats pretty good. But it probably dont amount to more than a hundred hours?

Or flip that around what about someone that drives a thousand miles a day? Completely wears out a vehicle in a year or two. is that unacceptable?

 

[Rock Crawler]

Go look at used garden tractors with the Tuff Torq K66 or the Hydro Gear G730. You'll be replacing engines before rear axles unless you are exceptionally hard on them or you are exceptionally unlucky.

 

[daugen]

I agree. In the 9th year, there is no liability for the manufacturer. We are NOT talking Tanaka air bags here...

Today I read a number of engines tout 1000 hour life expectancy. As if that's a huge deal...Well yeah, it might be for a B&S 500E that weighs about as much as a dinner roast, and lasts only slightly longer. Actually I have to admit the cheapo lightweight ditch mower I have is equipped with that engine, and amazingly it starts every time, thanks to liberal dosing of Sea Foam. But what are my reasonable expectations? This is a 300 hour machine. Max. The engine will lose power and the wheels/wheel bearings(assuming there was any...) will be shot. Yup, that's what I get for 179 bucks. Purely disposable machinery.

But if I spent two grand on a riding mower, maybe the real issue is what are reasonable expectations? It's a big issue for all of us.
Tractors thankfully are generally super reliable but lawn mowers normally aren't built to those standards. Want an 800 dollar push mower? well there's one out there and it's heavy to push but it will likely last forever with a Kawasaki engine on it.
But I'm not spending 800 bucks on a push mower any more than OP wants to spend ten grand on a John Deere or Kubota.

Cub Cadet says I have a K46 in my LT2, fab deck, Kawasaki engine, best of a price point breed. Bought the mower to give to a close elderly friend to use. I wouldn't own it, honestly I'm spoiled by better equipment, power steering, etc. But for 2 grand, which is a lot of money for families raising kids, should one expect ten years of reliable service? I'm not sure.
What do you all think?

I spent decades paying claims for insurance companies, have an interesting perspective on what folks think is reasonable.
Insurance is driven by contract law, lawn mowers? Caveat Emptor and Consumer Products safety, that's about all.

 

[fitterski]

The issue you are going to have is NOT the 300hr life.....

Its the 9 YEAR life. And IMO, most judges/jurys would find that to be perfectly acceptable for a lower end model.

I mean, what about things like kitchen blenders or a microwave? Get 10 years out of one and thats pretty good. But it probably dont amount to more than a hundred hours?

Or flip that around what about someone that drives a thousand miles a day? Completely wears out a vehicle in a year or two. is that unacceptable?

I can't comment on the legal aspect, that's for legal techies who WILL become involved if necessary, but I definitely do not consider 9 seasons (equivalent to 4.5 years in Florida for example), to be a reasonably acceptable life for a $3000+ mower. 40 years would be, as brought up I believe in connection with older Ford riders.

Other than that, I just talked to my dealer and my handle on the situation was a bit mistaken in that he had NOT opened the unit to evaluate the oil appearance; it was full and 'at the refill plug level' he saw no contamination. He had however seen condensation inside the transaxle contaminate the oil on other machines in the past, specifically while parked over the winter. THIS, he says, will be immediately obvious on opening but he will do nothing on his own or on my account. The climate here is in fact quite humid and cool as a rule, so with inappropriately designed venting this could well be at the root of the entire problem. I have no idea if just a purge and oil/filter change would fix it though, he seems to think not.