I tried STP in the steering box in my '55 2nd series 3100. It made the steering very stiff. It's "sticky", and it eventually ran out on my driveway. John Deere Cornhead grease is the stuff to use. Its "slippery" and stays put well.

'55 2nd series 3100 "Red Ryder" http://s1348.photobucket.com/user/c...&_suid=13893932572500736492512997429