In the factory G80?

As for drain plugs, I have two...one on the bottom of the pumpkin from the factory and one on my TA Perf rear diff cover.

FWIW, there was a TSB a few years ago in reference to switching the front diff fluid from the factory fill dino 80w-90 to synthetic 75w-90, as the viscous clutches in the transfer case were having a problem overcoming the thickness of the original gear oil in colder climates, and smoking transfer cases. I'm not trying to compare transfercases to governor lock differentials, but just trying to point out how sensitive the factory parts are to certain fluids

 

G80... With 75-140 Lucas... The rear is quieter and still works just as it should. There's a tru-trac sitting here waiting to either be sold or put in the truck if it ever runs again...

I know where the plug should be... And like I said, NONE of the rears I've ever had in any of my trucks have a drain there.... The Girdle cover that's going on has one though

 

Ha, maybe you found the secret to making a G80 last lol!