I have asked here about using it in the steering gear box and it seems to work good there. What if I were to fill my SM420 transmission with it? Would I run into problems? What about the rear end? I have that elusive HO72 with 4:11 gears and would hate to ruin that one as they are near impossible to find anymore.I only drive the truck in the summer, Never out there in Minnesota Cold , snow, Ice etc.This past winter in Minnesota it seemed was almost Forever. Some say Minnesota winter is 9 months of Tough Sledding! Then it is 3 months of road construction. The truck is usually in my heated shop over winter with me working on the projects I want completed for the next year. Jerry
