Small Engines (Lawn Mowers, etc.): Sabre Hydrostatic (overheating?), v belt pulleys, silver sheen

Question
Noticed hydro slipping on my 15hp eight year old Sabre, it is a hot day. Powertrain v-belt, pulleys and fan seem to be engaging and working fine. There was a couple of drops of fluid on the garage floor under transaxle. Is there an easy way to check fluid level? What about changing filter element. See:

http://jdpc.deere.com/jdpc/servlet/com.deere.u90490.partscatalog.view.servlets.H...

Note: Had the mower in for carb work and the idle and running speed came back high. Could running and sitting for a while idling high on a very hot day cause the transaxle to overheat and slip? Just adjusted carb, everything seems to run well but it is nighttime and cool. Should I be worried? Please advise if I should have it looked at ($25 for pick and delivery)or wait and see how it runs with adjusted carb?

Thanks a million - Great site!

Answer
Adjusting the carb has nothing to do with the transavle.  As hydro fluid heats up it expands.  When checking the fluid always do it cold.  Change the filter and check the oil for aluminum in the oil by leaving it set for a while.  If there is metal in it it will float on the surface and give the oil a silver sheen.  If there is there is wear in the transaxle and it should be done now.  If not keep an eye on it and get it to the dealer if it gets worse.