This is aggravating! I rebuilt my A833 gearbox and used all new gaskets from brewers and I filled it with oil and there’s a dang leak around the reverse detent housing to case gasket. So now drain all the oil back out to remove the sucker and try to figure out how to be certain it’s sealed this time. I used the gasket that brewers sent for it not sure why it’s leaking the mating surfaces looked smooth with no gouges or scratches.