TM 10-3930-669-34 1-20.  WHEELS AND TIRES. The drive axle is equipped with four wheel-and-tire assemblies (1 and 2), one inner (1) and one outer (2) per side.  Inner and outer wheel-and-tire assemblies are not interchangeable because of a difference in wheel depth.   The  steer  axle  is equipped with two wheel-and-tire assemblies (3), one per side. a Drive Axle Wheel-and-Tire Assemblies.   A wheel-and-tire assembly (1 or 2) consists of one tire and one wheel. The tire is solid, requiring no air. b Steer  Axle  Wheels.      A  wheel-and-tire  assembly  (3)  consists  of  one  tire  and  one  wheel.      The  tire  is  solid, requiring no air. 1-23/(1-24 blank)