Rear Differential Damage?

I was crawling under my ‘63 today, looking and learning. Found the “25” on my front dif, yep, a Dana 25. Then scooted back to the driver’s side of the rear dif and saw this... looks like maybe heat or something? No sign of any lube leaking, maybe from the casting? Botched repair? Maybe not holed all the way through, hopefully? Ever seen anything like this? A concern? Thanks for looking! Ray in central Texas.

 

I’m guessing it’s holding oil. Looks nice and clean in that area.

 

Yes, no leakage there or anywhere else for that matter. I was hoping some knowledgeable person would say, “oh yeah, that was pretty common back in the day”, ha.

 

Perhaps some PO attempted to mount something there? It's really hard to weld to cast iron, and a blobby failure seems possible.

 

Well, after scrutinizing that spot, it’s probably an original casting flaw, that’s my opinion and I’m sticking to it, ha. It’s not a thru-in-thru hole, no lube leaking, just looks bad. My idea is to do a JBweld repair, smooth it out nice and pretty and paint/grease-it to match, ha.

 

I think those are just the remains of the casting sprues. Probably not touched since they left Dana.

 

I think you’re exactly right!