Thanks in advance. I am finalizing the 1979 rear suspension swap into my 1975 and am at the point where I am prepping the craigslist 3.39 diff. My 1975 unit is pretty roached as the axle stubs have not only worn the c clips off, but have also begun to wear into the diff housing. Other than the gear set inside, it's not worth much. My plan was to open the 1979 diff, check the condition, remove the stub axles, put in new seals and c clips, then close it up and use it. Here are my questions: I opened the unit yesterday and it looks like the gear oil is green?! Everything looks great visually as the is virtually no wear on any of the teeth I can see, the axle stubs have almost zero endplay, there is no visible wear on the stubs after the c clips and the housing has surface rust but no breaks or cracks or any other visible damage. It looks almost like the unit was just rebuilt prior to me buying it from the seller who said it was sitting for 20 years. The ring gear still appears to have the yellow paint on the teeth. Maybe I'm an idiot for waking the sleeping dog. Can anyone chime in regarding the green color. Is this normal? Should I just close it up and leave well enough alone? I'm afraid to get too far into something I can't finish. The car is just a driver quality L48 convertible that's going to see good weather use...Also, maybe I'm an idiot part 2, but in my effort to get a better view of the internals, I drained the oil and sprayed everything with parts cleaner (Brakleen Red Can). Will this hurt anything in the long term? Should I flush with anything else before closing back up to remove cleaner residue? I took off a thin bead of black RTV that had squeezed into the inner edge of the case when I took the rear cover off. Should I use blue RTV on both sides of the new gasket (RTV on housing, mount gasket, RTV on gasket, mount rear cover. What are torque specs on cover bolts? I'm planning on wire brushing the bolts and washers. Should I use locktite on threads? There appears to be very minor moisture from the stub seals, should I just leave well enough alone or change them out as I am this far? Sorry for the picture orientation, but I took them with my iphone in the "normal" orientation and they appear turned like this. A lot of questions, I know, but I appreciate the advice.

 

I would go to the local parts store and get a new gasket and put the cover back on, sealant is optional. Fill it up with posi additive and gear lube and go with it. Nice find!