00 grade oil/grease was specified by GM
corn head grease is 0 grade (self-levelling grease)
cotton picker spindle grease is 00 grade (self-levelling and the correct specification for the GM steering box).
Many people find that steering-box leaks stop after draining out the gear oil and putting in the "thin" 00 or 0 grease (gear oil will almost always leak). If your pitman-arm shaft seal is bad, changing to grease might not eliminate the leaking.
