I run a few ride on's/garden tractors for our own domestic 3acre+ lawn/garden & others on the farms, all originally purchased in good low houred condition secondhand - Deutscher's (Aussie built rugged simple mowers belt driven direct gear drive transaxles with dual rear wheels/low centre of gravity making them very stable on steep lawn/hillsides), JD's (mainly because they're reliable, good value S/H, easy to maintain & there's a good dealer network), Kubota's (again reliable with good support) & Iseki's (arguably marginally better than Kubota's, but far less dealer support) - including:-
1.Deutscher R360 c.11hp Honda 36"deck c.25+yrs old & well in excess of 1000hrs (Engine change out & tranny rebuilt)
2.Deutscher R360 12.5hp B&S 36" deck c..25+yrs old & well in excess of 1600hrs ( New rings in engine & tranny rebuilt)
3.JD LT155 15hp Kohler 38" deck c.10+yrs old (now running rear Carlise Turf Master tyres for added traction) over 1100hrs without componet change out/rebuilds/failures
4. Not pictured- JD LT155 15hp Kohler 38" deck c.10+yrs old (running rear Carlise SL Super Lug tyres, specifically set up for max. stability/traction for mowing on damp clay soil around a undulating pond bank, approaching 800hrs without componet change out/rebuilds/failures
5. JD415 16hp Yanmar Diesel 54"deck & Catcher c.250hrs & around 8yrs old
6. Kubota 7100 HST 4wd 16hp Diesel whilst shown with the backhoe fitted, is usually run with 60" mid mounted deck & rear TPL 36" slasher (i.e. bushhog) c.800hrs & maybe 20yrs old ?
7. Iseki TX2160 Manual 3x2 G/box 16hp Diesel runs a 48" rear TPL mounted finishing mower or 36" slasher c.450hrs & maybe 15yrs old
As for maintenance, like our farm gear I tend to probably "over-maintain" in most people' s view, as I'd rather invest my time in keeping what I have in good order than have "downtime" or search for replacements.....
I wash/wax this gear only max. once/year, using a garden blower to initial clear debris off after use & then completely clean with compressed air after every use (I avoid using water for cleaning because IMO it causes rust ), & also do the following regular basic maintenance (a few extra $'s in oil & lubes + a little extra time seem cheap insurance compared to rebuilds/replacements):-
1. Every 50hrs max. change engine oil filter & replace oil with premium synthetic product
2. Every 10hrs max. clean air filters ( if applicable reoil), replace every 100hrs
3. Every 10hrs max lubricate spindles with high temperature bearing grease(rubbish in my humble opinion any spindles are sealed ( in so called "sealed" units zerks are retrofitted) or supposedly lubricated for life by the factory ) /lubricate steering/axles/linkages with graphite moly farm grease
4. Every 100hrs flush transmissions & replace oil with premium synthetic product (including those hydro tranny's supposedly is sealed for life, the way I see it : oil breaks down, & hydrostatics hate heat & degraded oil so it's cheap insurance & relatively easy to do on so called sealed unit)/adjust drive belt & clutch
5. Every 6 months drop the decks & paint with 2 coats of penetrol & then 2 coats of industrial gloss black paint to prevent rust/adjust deck belt