TM 10-3930-659-20 1-11. EQUIPMENT DATA (Con't). Table 1-1.  General Characteristics and Specifications (Con't). Transmission Specifications: Type ................................................................................................................ ZF of North America, ............................................................................................................................ Countershaft, Power Shift Forward Speeds  .................................................................................................. Four Reverse Speeds .................................................................................................. Three Torque Converter Type ........................................................................................ Single Phase, Single Stage System Pressure @ 1500° ± 100 and 1500 rpm  .................................................. 213-242 psi ............................................................................................................................ (1469-1669 kPa) Axle and Differentials Specifications: Type ................................................................................................................ John Deere, Inboard Planetary Axle with Standard Spiral Bevel Gear Differential Differential Gear Reduction Ratio ........................................................................ 4.333:1 Inboard Planetary Drive Reduction Ratio ............................................................. 4.800:1 Overall Axle Reduction Ratio  .............................................................................. 20.798:1 Service Brake Specifications: Type ................................................................................................................ Wet Disc Operation  ............................................................................................................ Hydraulic, Foot Pedal Accumulators: Charging Medium .................................................................................... Dry Nitrogen Charging Pressure  .................................................................................. 475-525 psi ............................................................................................................................ (3275-3620 kPa) Parking Brake Specifications: Type ................................................................................................................ ZF of North America Operation  ............................................................................................................ Manual Foot Pedal Mounting  ............................................................................................................. Transmission Tire Specifications: Size ................................................................................................................ 17.5-25 Type ................................................................................................................ Tubeless Ply Rating ............................................................................................................ 16 Recommended Inflation Pressure: Front ....................................................................................................... 55 psi (379 kPa) Rear  ....................................................................................................... 40 psi (276 kPa) 1-6