I know nothing about a hydrostatic transmission in a mower, but have always wanted one.
Please give me some advice on them, such as dependability, can they be serviced, repairs, etc.
If I were buying I'd have to go with a Craftsman or similar probably.
Thanks for your help...

Hydrostatic, a fancy term, has been used for decades. You ever wonder what spins the drum on a concrete truck? If you have a chance, later when the weather warms up, you may go visit a concrete plant, and We are sure that the plant manager will be willing to show. After all, concrete truck driving is one of the most hazardous occupations in this make-believe world. They are always looking for drivers. And, the wet kit hardly ever breaks down.
Now, the basics consists of a hydraulic pump, with internal bypass (static) and the motor, driven by some pressure, depending on the position of the load, or spool valve. And, since the valve controls fluid flow, providing reverse; technically, there is no neutral. This is why on new riders with "automatic," One needs to set the parking brake before the engine will crank- safety starter interlock.
10W hydraulic oil was all we ever used in wet kits- no different than the lowly old 1/2 ton bottle jack. We are suprised that the tuff torque 46 requires a 5w50. Strange. We didn't know a 5w50 existed. Boy are we getting old!i lived on a hobby farm of <7 acres for over 10 years. i had both the belt driven 3-speed transmission and the hydrostatic drive system. the transmission style :thumbdown: gave up after 3 years. the hydrostatic :thumbsup: i had, i bought used. the machine was about 20 years old, so i drained the oil(after running it for about 30 minutes), replaced the oil with a non-detergent 10W(suggested by the dealership that i called) and been running it for 5 years now. i have not had any problem with it as of yet. thing you have to think about is now most transmission style now have an aluminum gear case, where as the hydro's are either a higher quality aluminum or steel casing's. also depending if the model you are getting if you are going to use it for a hobby garden or blowing snow, i would suggest the hydrostatic drive.
Ok, now, we are stupid. Just what is a Hobby Farm? Can you please enlighten us?
Thanks midnite rider. Had heard the expression before, but thought it may have been a nickname, or slang term.According to my favorite source Wilkepedia:
In the US, as farms grow in size, older farms become less economically viable. Some are purchased and most of the land combined with larger nearby farms, however the large farm has little use for the buildings. These can be sold off with only a building lot of real estate, but are much more saleable if a modest area, 5 to 15 acres (20,000 to 60,000 mイ) is sold along with them. These are usually snapped up quickly by people with well-paying city jobs who wish to live in the country, or to retirees, who wish to be active as part time farmers.