Ok, my first post...In looking over my "new" ride I have discovered that the rear has no fill hole...I can see a place on the center section facing from the front side, where a plug could be be.. but no plug..I have looked all over the center section and the housing...no fill plug to be found. I know nothing about Ford 9", but I guess that some center sections have fill plugs and some housings have a fill plug and I have a miss matched setup. Funny thing is I discovered this after replacing the driver side axle seal (because of lube all over the inside of the tire), my guess is that someone over filled the rear through the only hole I've found...the vent hole in the top of the axle tube...The old seal I replaced looked ok and when I pulled the axle no additional lube ran out??? I guess it leaked till it reached the correct level???lol..... Anyone have any idea's other than replacing the center section?? Sorry for the long post...........Chris