GE Washer WDSR2080D5WW Transmission oil leak

the washer was found to have a good amount of oil standing underneath. The trans appears to havr a bad seal where pieces bolt together on the end of trans that is closest to the tub. Is this not replaceable? It seems the whole unit is for sale but nothing less than that. When running its clear that air, oil is escaping. Is standard gear oil ok, are there any nylon gears inside?