When fill the steering gear box use only standard GL-4 hypoid type gear oil, SAE 80W or SAE 80W/90.
Check the level of the lubricant in the steering gear every 12,000 miles (15,000 miles, 1979 and later). If the level is low, check for leakage. Any oily film is not considered a leak; solid grease must be present. The lubricant is added and checked through the filler plug hole in the top of the steering gearbox.