I rebuilt the manual steering gearbox in my Pontiac, back in the early 1990s. Was told to use CV axle grease because it's kinda liquid yet thick and super EP, being designed to keep Rzeppa constant velocity joints alive. I think I put a pint of it in there, but that was passenger car size versus truck size. It worked, too. Buttery smooth steering for years after, and never leaked a drop.
