I have a 1995 JD STX46 hydro, with unknown hours or maintenance history beyond the 5 years I have had it. I have changed the transmission oil twice and the hydro drive belt with a Stens about 4 seasons ago. I am thinking that my hydro is on the way out when last night a friend of a friend says try the belt because JD uses a pitch that the aftermarket belts don't match, I am not sure that the belt would make the machine behave like it is...
I get about half way through mowing my flat front yard, 10-20 min and the tractor starts to slow down and looses reverse. I keep pushing it waiting for it to just stop (all the while thinking my neighbors are going to think I'm nuts when I towing this thing around with the 2520 to finish mowing). It will keep going at its very slow pace and by the time I finish the front and side yard maybe another long 10-15 minuets and head for the back yard the STX is back to just about normal speed and it will even reverse up the hill in the back yard. It does not do it every time out, air temp does not seem to make a difference, the case is always pretty clean and fan operating correctly. I changed the hydro oil with the Tuff Torq recommend 5W-50 synthetic engine oil last summer, I thought maybe the 4 year old oil I put in was breaking down and some fresh oil would help, it didn't. The hydro does make noise and is worse in reverse than forward.
Any thoughts? Anyone see a belt making this happen?
I know I can rebuild the hydro for about $350 with a kit from Tuff Torq but I have about $800 total into this thing over the last 5 years and it's 23 years old. It might be time for a new zero turn and keep this as a couple times a year leaf vac. Any opinions on that would be welcome.