Axle tube leaking where? At the wheel side? Could need axle seals?
x2, at the pumpkin there is not much you can do. Factory didn't do full circumference welds, only plug wit interference fit. if not show then carefully weld the circumference careful not to warp the assembly.When I do restoration work on these old 12 bolt housings I sandblast them, then shoot three coats of SPI epoxy, wait 12ish hours, then use 3M Ultrapro URETHANE seam sealer on the spot welds and housing around the tubes-not enough to even know it's there (judged cars) but enough to fill the void so it doesn't have a chance to leak, then one more coat of epoxy primer, then paint. They never leak. Epoxy primer and a quality urethane seam sealer is key. Epoxy primer is fuel and oil resistant.