1980 12bolt leaking at what looks like plug welds or ? Lower rear, near where axle tube goes into housing. there are about four of these "plugs". How do I plug this leak. Anybody ever had this? I never have seen this before. Just cleaned painted, sealed and filled unit. Damn it! Are these holes for casting purposes or to weld tube to housing? How are they sealed at factory? These are round, smooth, slightly raised, 3/4 diameter spots about 4-6 places. Only one leaks. thanks.