OPERATING IN DUSTY OR SANDY AREAS
General. Be aware of vehicle overheating when operating in dusty or sandy areas. Air cleaner, cooling system,
and lubrication points will require frequent servicing.
Do not use tire chains in soft sand.
Use a second vehicle with winch to recover
vehicles stuck or sunk in sand.
When starting in sand or soft ground, place transfer case shift lever (6) in low range and transmission
selector lever (5) in 1-2 (second) or 1-3 (third).
Deflate tires to 25 psi (172 kPa) only when operating off the road in heavy rain. Inflate tires immediately to
correct pressure when operation changes to paved roads. Refer to table 1-10 for tire inflation data. Refer to paragraph 3-
11 for inflating tires using vehicle air system.
On M939A2 series vehicles, select SAND (8) on control panel (7). This will automatically deflate tires unless
20 mph (32 km/h) is exceeded (15 mph (24 km/h) on M936A2 wrecker) for more than two minutes. CTIS will then
automatically inflate to cross-country pressure.
Accelerate slowly so wheels will not spin and dig into sand.
Inflate tires to normal pressures after vehicle has cleared deep sand
(table 1-10). On M939A2 series vehicles, press the desired mode select button on the
control panel (7).
When moving across a slope, choose the least angle possible. Keep
moving and avoid turning quickly.
Keep throttle steady after reaching desired speed.
Do not rock vehicle out of deep sand.