Running 140wt in 300E Diff?
 

Okay, lets try again, I am wondering if multi-vis lube, like a 75w-140 wt would be acceptable for my rear diff. The owners manual says 85W-90, I haven't wseen that, there is plenty of 80W-90 etc. Does GL-4 or GL-5 make a difference? Thanks again.....

Use GL-5. Castrol Hypoy C 80w90 or Valvoline 80w90 are available at Wal Mart, AutoZone, PepBoys, Advance Auto, etc.