TM 10-3930-664-24 d. Transmission Stall Check. CAUTION Ensure that the vehicle does not move unexpectedly when operating the engine and converter at stall RPM. (1) Place the vehicle against a solid barrier, such as a wall, and/or apply the parking brake. (2) Block front and rear wheels. (3) Place directional control lever in FORWARD or REVERSE position as applicable. (4) Place speed control lever in HIGH. (5) With  engine  running,  slowly  increase  speed  to  approximately  one-half  throttle  and  hold  for  30  seconds. Place speed control lever in NEUTRAL. CAUTION Excessive   temperatures   +250°F   (120°C)   will   cause   damage   to   transmission   clutches,   fluid, converter,  and  seals.    Do  not  operate  the  converter  at  stall  condition  longer  than  30  seconds  at one time. (6) Operate the converter at stall condition no longer than 30 seconds.  Shift to NEUTRAL for 15 seconds and repeat then procedure until desired temperature is reached. 4-4