I have a John Deere 170 skid loader. It runs good except now there is oil dripping from the variable speed drive sheave. This is causing hydrolic oil to get on the drive belt and then the drive belt slips. I had the seals replaced in this sheave a few months back and the shop told me the hydrolic shaft and piston that push the pulley together are getting worn and the seals may not hold. John Deere indicates they are not able to get a new drive sheave assembly since they are obsolete. I like the loader and cannot afford to get a different one. Does anyone know how to fix this?