Has anyone ever experienced this? Somehow water got into the diff case, and i only discovered it today when i noticed the diff wasn't rotating smoothly. I've not checked the front diff yet... []

The diff was in PERFECT condition before i took the truck to the track on Sunday - the track was wet, but it wasn't like i was driving through a river! Didn't spend more than 10 minutes driving the thing! The bearings feel like sandpaper but the teeth look ok.

Is there anything i can use which will get rid of the rust? I don't really want to buy a whole new diff...