TM 9-2320-386-10 2-89 2-37. OPERATION IN DEEP MUD 1 a. General. CAUTION Do not attempt operation when only one driving wheel is equipped with tire chains. Doing this may result in damage to tires and powertrain. (1) Prolonged operation in deep mud requires the use of tire chains on driv- ing wheels. Refer to FM 21-305 for installation of tire chains. (2) If tire chains are not available, deflate tire pressure to 18-22 psi (124-152 kPa) (para. 2-19). b. Before Operation. (1) Perform “before operation” PMCS (table 2-2). (2) Place ECU (1) to “S” (sand/mud/snow) setting to deflate tire pressure to 18-22 psi (124-152 kPa). c. Driving Vehicle Cross-Country. (1) Start engine (para. 2-12). (2) Engage front wheel drive (2) (para. 2-3). NOTE When placing the vehicle in motion in deep mud, ensure front wheels are in straight-ahead position. (3) Place vehicle in motion (para. 2-15) with transmission select lever (3) in “1” (first) position, and transfer case shift lever (4) in LOW position, and release parking brake lever (5). Begin movement gradually, without causing wheels to spin or engine to race. (4) If rear end skidding occurs, turn steering wheel in direction of skid. Let up on accelerator pedal (7). Pump brake pedal (6) gradually to recover from skid. (5) Be prepared to downshift transmission select lever (3), if necessary, to prevent vehicle from getting stuck in mud. 2 6 7 4 5 3