TM 10-3930-669-20 4.  TRANSMISSION MALFUNCTIONS IN FORWARD AND REVERSE (CONT). KNOWN INFO Transmission control switches OK. Transmission operates normally In neutral. Transmission oil temperature gauge OK. Transmission speed switch OK. Transmission forward and reverse solenoids OK. Tachometer OK. inching valve OK. POSSIBLE PROBLEMS Low transmission oil pressure. Transmission oil temperature high. Universal joint(s) wom. High range solenoid faulty. KNOWN INFO Transmission control switches OK. Transmission operates normally in neutral. Transmission oil temperature gauge OK. Transmission speed switch OK. Transmission forward and reverse solenoids OK Tachometer OK. Inching valve OK. Transmission oil pressure OK. POSSIBLE PROBLEMS Transmission oil temperature high. Universal joint(s) worn. High range solenoid faulty. TEST OPTIONS Pressure test and STE/ICE-R #10. REASON FOR QUESTION If transmission oil pressure is low, transmission has an internal   leak,   and   forklift   will   not move forward or rearward when transmission control lever is placed in forward or reverse. TEST OPTIONS Visual Inspection. STEACE-R #38. REASON FOR QUESTION If transmission oil temperature is high, transmission may have an internal failure. TM  10-3930-669-20