72 Pinto Station Wagon - I removed rear differential cover, drained gear oil, put on new gasket, replaced cover. I cannot find any way to replace the gear oil. There is a "breather" hose on the top center of the differential with a small rubber 10" long hose that goes up into a crossmember. I tried to add oil thru this hose, no good. Then removed the fitting for this "breather" on the top of the differential housing and my next effore will be to attempt to dribble a quart or so of gear oil thru this tiny fitting hole. I have to believe that this is wrong. I cannot find any other fittings on the rear end/differential housing anywhere to add oil. Just this little fitting with a hose that goes off the top center of the housing. If they are there I must have missed them. I may go crazy here. Help. Thanks jt