I am getting ready to get my car to the rolling stage and have a problem. After sandblasting my 12 bolt rear, I noticed that there was rear oil seeping out where the axle tube is pressed into the pumpkin. Is there anyway of fixing this??or is it a common problem that I will have to put up with.

I certainly wouldn't put up with it. I hate oil leaks. Some people weld the tubes to the center section, but I think it takes a pretty skilled welder when dealing with cast iron. I'm sure someone will recommend a good sealer to use, perhaps even a good silicone would do the trick. Make sure the surfaces are as clean as you can get them - I like to use brake cleaner. I'd also check to make sure that you didn't get sand into your differential!

When I split the exhaust manifold on an old 230ci straight-six, I used a nickel welding rod. Worked out great.

I heard you could weld the cast and steel together, but welding isnt my expertise. I'm not sure if running a bead of silicone is going to stop it. I guess I dont want to put this all together and find out that it's going to leak and have to pull the rear out of the car again to fix it. Anyone have this experience?? HELP!!!!

As stated earlier, you need to get it fixed, it will leak.

As BPOS suggested, nickel brazing rod works well, but, finding the talent at a local weld shop will be a good task. This would be the best route. And if you have it done to one side, do the other side.

Then check the housing for squareness between the two axle ends. Front ot back measurements should be the same as top to bottom measurements. What I mean is: 1. set the housing on a couple jackstands; 2. C-clamp a 2-3 foot long piece of approx 1" sq tubing to the housing flange on both ends, tubing are on the same plane; 3. measure the very ends of the tubing the width of the housing, record measurements; 4. rotate the sq tubing 90*, and measure and record again. Each axis of measurement should be less than 1/8 inch difference.

Another route of repair would be to soak the suspected area with lacquer thinner to clean the area. Then, visit a body shop and ask them to fillet a bead of 3M Liquid Steel adhesive about the circumference with the housing standing on end and let set for 24 hours. Turn housing over and do the other tube. Dries really hard, self-sealing, self leveling and is paintable.

Thanks everyone. Thanks Everett, you are a wizard!I think I can find a place to weld it and make sure it's square. graemlins/hurray.gif

Almost all of the old GM rear ends leak around the axle tubes because the tubes are pressed into the center casting and then plug welded in 3 places. The oil seaps out through the crack around the tube. Later rear ends had sealant applied to the inside of the casting before the tubes were pressed in and this seems to have pretty much cured the problem. If you want the housing to look original then you may not be able to do anything about it. If you don't care how it looks then you can have it welded by someone who has experience welding cast iron. By the way, oil also leaks out of the plug welds.

Hey Jonesy how about chewing gum? or duct tape? graemlins/clonk.gif

It's only leaking on the drivers side and it is also leaking out of the plug weld on the same side. What a bit*ch. So, I can probably weld up the plug weld and the axle tube. I guess that looks like the right thing to do.

Click, what kind of gum? :confused: Just in case the welding doesnt work :D

Maybe some of that synthetic rearend oil will help seal it up graemlins/thumbsup.gif

The plug welds are nickel.

When I put an 8.5" 10 bolt in mine a few years ago, I had the tubes welded to the center for two reasons. I could see that the tubes were leaking, and I read that welding the tubes to the center makes the housing stronger. I saw in one of my magazines where some guy had an early 70's Camaro that ran the 1/4 mile in the nines with a 8.5" rear. One of the mods he did to the housing was weld the tubes at the center. I had this done by a reputable machine shop in my area for $ 60.00. They supposedly braced the tubes to prevent warpage from the heat of welding.