922B loader TLC turbo rebuild pre cups

Hi Guy's I working on giving my hard-working loader some TLC as she never let me down so I have to show her some love. on the to-do list are turbo, pre-cup seals, brakes wheel cylinders, and maybe some electrical. the turbo is off 922B 59A4168. Garrett 4M0289 serial number 00304. it was leaking oil into the cold or intake side of the turbo as well sometimes I think I could hear the impeller touching the housing.  I measured the end play .004-.005 endplay and .012 radial play.  getting ready to put things back together and I am not sure how the Hot side of the turbo seals the oil in. it looks like there 3 groves that may have cast iron piston rings but can't see or find anything in my parts book showing them.  second thing where does the oil hole in the turbo shaft go to? I got the hole cleaned out but not sure if there is another one that is blocking that I not seeing. here are a few pics as I know everyone loves them
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the 3 groves that may have cast iron piston rings but can't see or find anything in my parts book showing them or is it like a labyrinth seal and the exhaust pressure keeps the oil on the inside? there's .010 clearance between the shaft and the I.D. of the housing. could there be a O ring missing off the shaft in the grove by the O ring pic ?
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