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Hydrostatic vs Automatic transmition

45K views 15 replies 13 participants last post by  94strokerace  
#1 ·
I'm looking at a rifding lawn mower and one says it is an automatic and the other says it is hydrostatic. What is the difference? Is one better than the other? thanks.
 
#2 ·
It would help to know what brand & model of lawn mower. A hydrostatic is VERY handy in about 90+% of the things I do with My garden tractors. They're older (43, 40, & only 28 yrs old) and the newest one is Hydrostatic, built by Sundstrand, in a CC 982. Most of the green tractors (jd) used the exact same hydrostatic unit. And they are 100% bullet-proof. They use a gear type pump to charge the piston motor and the motor direct gear drives the differential in both brands....but the Cub Cadets used a stronger axle than the little Dana JD used.

First Cub Cadet made with a hydro. trans was the model # 123 first built in 1966 and there's still a LOT of them running around every week mowing yards. As long as the fluid was changed regularly, manual recommends every 100 operating hours, but as long as They got fluid & filter every 5-10 years, they still work fine.

An "Automatic" trans could be most anything....but I'm pretty sure it won't shift like the A/T in a car or truck. And I envision something with all kinds of belts & springs to cause problems.
 
#5 ·
I have a hydrostatic Kubota and wouldn't have it any other way.The shifting days are over (except in my truck).
 
#6 ·
I've got a kubota with a hydro as well...Works very well, gets a little whiny sometimes but not bad...Very versatile and a great tractor
 
#7 ·
Some info for you. You can save some money by buying a Huskee, Craftsman, Cub Cadet rather then that White. Why because they are all made by the same company MTD. They are just painted different colors and have different names on them.

Also do yourself a favor buy the hydrostatic. It will last longer then the automatic.
 
#8 ·
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Have had one just like this since 1989 when I bought it brand new. The owners manual says not to service the fluid in the transmission. I have taken them at their word and never touched it. This thing has the Kawasaki engine and runs flawlessly. I have had to replace two tires and two wheels since I bought itand that is it.
 
#9 ·
mtd's automatic is a dual-belt variator setup...there is a sheave between the transmission and engine that changes the drive ratio as you move the lever (basically you have 2 drive belts to run a one speed transmission-very crude and not all that reliable)

a hydrostatic is as described, basically a hydraulic pump (usually a piston pump) charging a second piston pump that has it's output controlled by a swashplate which is connected to your pedals or lever (depending on model)...having 1 pedal or 2 doesn't change what kind of transmission it is (though you'll find that having a single pedal is much less comfortable than split pedals)...as far as reliability goes, keep in mind that a good hydro on a larger garden tractor can cost over $2,000 just for the transmission so it's not like you're buying some heavy-duty piece of equipment...most of the less expensive hydros are not servicable and you can't even add fluid without splitting the case halves (which is ok as there's less chance of dirt entering the oil), but if you only use it for mowing and don't try to move the boat or drag the driveway or things like that you'll get good life out of it...
 
#12 ·
........but if you only use it for mowing and don't try to move the boat or drag the driveway or things like that you'll get good life out of it...
Dang, I've been moving the boston whaler around the property with my Sears Crapsman mower for over 10 years. I even mounted a 1 7/8" ball on it. When the mower deck was shot I dropped it and tossed it and keep the tractor for moving the boat, log splitter and small dump trailer around the property. Moved a lotta dirt with that thing. Still going strong. :beer_yum::beer_yum:
 
#11 ·
ayp used to make craftsman mowers....they are now produced by Poulan which is owned by Husqvarna...
 
#14 ·
Of the 500 hours on my hydrostatic kubota over 350 of them are from moving nothing but boats.It is also a L3130 so there is a differance from a small garden tractor.
 
#15 ·
The "automatic" transmission either uses belt slippage (yes, belt slippage) or it uses a setup similar to a CVT only your foot pedal controls the belt tension against a pulley that moves in or out based on the amount of tension as opposed to flyweights on a CVT.

A hydrostatic is all mechanical.

John Deere uses both "hydrostatic" and "automatic" setups and both are incredibly reliable

However.....the hydrostatic is better at pulling heavy loads and you won't find an "automatic" setup on a garden tractor that is also intended to pull trailers and push blades and such.


The hydstatic setup is simple. You have a pump driven by the engine and another pump which is driven by fluid from the pump from the engine thus making it a motor.

Your foot or hand control changes the angle of the swashplate on the pump thus controlling the volume of fluid reaching the "motor".
 
#16 ·
my grandfather's Simplicity was passed on to me. its a 1978 7016 Hydrostatic (Sunstrand pump, 16hp Briggs&Stratton). the tractor wasnt equipped w/ an hour meter, and one wasnt installed until i got it in 2000. i have put close to 800 hrs on it mowing my 3 acres,and occasional handy work around the house with the wagon or scraper blade. there is no telling how many hours my grandfather put on this thing over the 22 years he had it. he mowed his pasture with it, cut his grass, vacuumed the leaves up with it in the fall, removed snow from his driveway, plowed/cultivated his garden, well, you get the point. there is no telling how many thousand hours are on that transmission. it doesnt leak a drop of oil and works flawlessly 30 years later.