lubranoc

I bought a 4th gen 3.23 disc rear a while back and I am finally ready to work on it a bit and put it in the car.

Here is what I plan to do:
Remove all brake parts, brake lines and sway bar.
Power-wash it get all the dust and crudd off of it.
Sandblast
Weld axle tubes
POR-15 the whole thing
Check\ overall pinion health (What should I look for other than metal shavings, gear lash and gear patter on pinion ?)
install with new aluminum cover
replace fluid
Replace brake lines
Put LT-1 rear brakes back on
Put Sway bar back on

Before I did all that I wanted people to take a look at these pictures of where the tubes met the center section and get some opinions. Is the crud circled in red where factory welds are leaking ? If so, will welding the axle tubes fix this ?

Searching the forum I read different opinions regarding the importance of having the rear end in a jig when the tubes are welded. Knowing that I only have access to a MIG welder, if you feel that having the rear in a jig is key to keeping the tubes straight I would like for you to provide a sketch or ideas on designing a jig that I could make at home with the MIG welder.

Thanks
Chris

big gear head

Yes, that is where the plug welds are leaking. No, welding the tubes will not fix it. It is my opinion that it is a waste of time to weld the tubes in a 3rd gen Camaro rear end because the torque is transfered through the torque arm and not the axle tubes. First and second gen Camaros transfer the torque throught the tubes, but not the thrid and fourth gen. Welding the tubes requires some special skils and nickel rods. Welding mild steel tubes to a cast iron center is not a job for a novice and should not be done with a MIG welder. There is a lot of prep work involved with welding cast iron.

A housing fixture does not require any welding. It is a long straight shaft that is ground true with machined bushings that fit into the bearing bores. Making a fixture requires the use of a lathe.

lubranoc

Thanks for the info.

Since welding the tubes won't resolve the leaking, is there any way to stop the plug welds from leaking ?

Thanks

big gear head

You might try cleaning the housing out in a hot tank and put some epoxy around the seam on the inside where the tubes are pressed in. There is no way of that I know of to seal it from the outside.

lubranoc

Thanks for the info. How bad is this type of leak ? is the rear end junk or is this fairly common ?

big gear head

It's very common. I'd say that every GM rear end with plug welds in the axle tubes does it. Some more than others.

lubranoc

what is the function of the plug welds ?

big gear head

The axle tubes are pressed into the center casting and then plug welded with nickel wire to hold them in place.