OPERATING IN EXTREME COLD (Contd)
Start engine when engine coolant temperature reads 120°F (49°C) or higher as indicated by engine
coolant temperature gauge (1). Refer to paragraph 2- 13 for cold weather starting instructions.
Check instrument readings. If any reading is not normal, stop engine. Report condition(s) to
organizational maintenance if operator troubleshooting (table 3-1) cannot correct malfunction. Normal instrument readings
Engine oil pressure gauge (7) should read 15 psi (103 kPa) on M939/A1 series vehicles and 10 psi
(69 kPa) on M939A2 series vehicles, or higher with engine idling.
Air pressure gauges (2) should read 90-130 psi (621-896 kPa).
Voltmeter (3) should read in green area.
Engine coolant temperature gauge (1) should read 175°-200°F (79-93C).
Do not allow the M939 series vehicles to
exceed 5 mph (8 km/h) or M939A1/A2 series
vehicles to exceed 6 mph (10 km/h) when
transfer case is in low and the transmission is
in 1 (first). Failure to do so will result in
damage to internal engine components.
Drive slowly with transfer case shift lever (5) in low range and
transmission selector lever (4) in 1 (first) for 100 yd (91 m). This should be
enough time to warm up gearcases and tires.
Check instruments during operation. Refer to step 2c for
normal readings. Transmission oil temperature gauge (6) under should read
120-220°F (49°-104°C) for normal operation.