D6D left final leaking

Left final needs seals. I know this is a huge job. I tried to tighten the axle nut, heard everything from tight as you can with 6foot bar, and tight then back off 1/4 round. Any guesses? I've been trying to run cornheader grease in it, grease when you pump it, then turns to 90w when it gets hot. Can't keep oil in it even 90w all day. Need to finish job before we drag it back to shop. Any suggestions or tips? Or just park it and fix it before I tear up more?

D6D left final leaking