Small Engines (Lawn Mowers, etc.): Hydro Gear Model 319-0650, craftsman 917, transaxle

Question
This transaxle unit (Hydro-Gear Mod#319-0650) has a removable check valve.  If I can remove the transaxle from the mower(Craftsman 917.259572), can I turn it upside down and drain the fluid using this check valve?  Then turn the unit right side up and refill the transaxle?  I don't see any other plugs or access of any kind on the housing.  Also, ok to use 20W50 engine oil?  I believe the capacity is 81oz.  Any help would be greatly appreciated.

Answer
You should be able to drain the old oil and refill but you may have to purge the system to get the air out.  Have you checked out Hydro-Gears webe site.  Might not have the exact transaxle but you might be able to find a very similar unit.

http://www.hydro-gear.com/Main/service/service-repair-manuals

I'll keep searching to see if I can find some more info.

Eric