So this weekend I drained the front diff and filled it with M1 75 w 90. When I unsrewed the fill plug oil started pouring out immediately. I was on the street, and figured the truck was on a bit of a decline. I put in about 2.5 US quarts (the FSM calls for 2.8 for diff's w/ lockers). After driving around for a day I felt uneasy about not putting in more. This time I parked the truck in a buddies garage, and I planned on filling it until some oil poured out. The diff ate another quart of oil without any running out of the fill hole! I'm wondering if there's a seal inside or something that has gone bad, thus draining the diff oil into some insatiable sink. I pulled that explanation out of my a$$ b/c I'm not familiar with the inner workings of the axle. ANyone have a similar experience? While I had a roof over my head I swapped out the PCV valve...that grommet sucks to change, I went straight to step #6 after that.
Cheers.
Cheers.