changed out the gear oil in my rear diff yesterday and drove to work to find gear oil sprayed up under the bed. Looks like it is coming from above the diff. and spraying down on it. Maybe the axle vent? Not usre what is going on with this. Any help you can give is appreciated. Gotta drive home soon. thanks guys.

 

IMO...you over filled the rear end...

 

X2 ( Yep I overfilled mine when I added the friction modifier and blam out the vent tube it came spraying ... And friction modifier stinks like a ****... Good news though it only sprayed a little out , then I washed the underside of the truck and no more spray ...

 

I kinda figured it might be the axle vent just throwing out the excess but I wasn't sure. I've got some cleanin to do! thanks again.