Rear End Leak
 

My '61 GMC 1000 has a Ford 8.8 inch rear end. It has leaked since I owned it. I took the cover off, cleaned the sealing surfaces well, installed a new gasket and filled with fresh oil. The next morning I found a bead of oil at the bottom of the gasket. The gasket was not the culprit though.

I cleaned and wire brushed the entire gear chamber as well as where the axle tubes were joined to it. I watched the entire area and before my very eyes I saw oil seeping through on one side of the axle tube's weld plug. The weld was porous and it was allowing oil to actually seep through at a slow rate.

My first inclination was to grab the welder and re-weld it. After reading up on the dangers of that causing worse problems, I elected to drop the fluid level below the axle tubes and clean the offending dime-sized weld plug with carb cleaner as well as the axle tube joints. I then used black RTV sealant to completely seal the weld plugs and both tube joints. The type of sealant remains flexible. It has been dry ever since. One for the books.