TM 9-2320-387-10
2-40. OPERATING ON UNUSUAL TERRAIN (Cont'd)
b. Unusual Terrain Driving Techniques.
CAUTION
Do not shift into any lower gear than is necessary to maintain head-
way. Attempt to maintain a constant engine speed. Over-revving
engine will cause the wheels to slip, and traction will be lost.
Before ascending or descending steep hills, stop vehicle, place trans-
mission to N (neutral), and shift transfer case to L (low range). Failure
to shift transfer case to L (low range) before ascending or descending
steep hills may result in damage to drivetrain.
Operating vehicle in H/L (high/lock range) or L (low range) with
uneven tire pressures on hard top surfaces where the wheels cannot
slip to equalize rotation may cause driveline torque buildup, difficulty
in shifting, or damage to vehicle components.
(1) Before climbing a steep hill, shift the transfer case into L (low range) and
the automatic transmission into 1 (first). If wheels start to slip, walk the vehicle the
last few remaining feet of a hill by swinging the front wheels sharply left and right
if situation permits. This action will provide fresh "bite" into the surface and will
usually result in enough traction to complete the climb.
CAUTION
When L (low range) is used for engine braking while descending steep grades,
avoid sharp, continuous turns. Failure to avoid sharp, continuous turns while
operating transfer case in range may cause damage to drivetrain.
(2) You can proceed safely down a steep grade by shifting the transfer case
into L (low range) and the transmission into 2 (second) or 1 (first). Let the vehicle go
slowly down the hill with all four wheels turning against engine compression.
.WARNING.
Do not travel diagonally across a hill unless it is absolutely necessary,
or injury to personnel or damage to equipment may result.
(3) When moving across a slope, choose the least angle possible, keep moving,
and avoid turning quickly.
(4) After shifting from locked ranges, always back up for a distance of
approximately 5 ft. (1.5 m) before proceeding to prevent driveline torque buildup.
.WARNING.
Starting aids will not be used on the engine. Use of starting aids may
cause damage to vehicle and injury or death to personnel.
.WARNING.
Do not use the hand throttle as an automatic speed or cruise control.
The hand throttle does not automatically disengage when brake is
applied, resulting in increased stopping distances and possible
hazardous and unsafe operation.
Do not fully apply hand throttle when engine is not under load.
NOTE
If engine cranks slowly and voltmeter indicates low battery charge
level, attempt to slave start vehicle (para. 2-23). If vehicle still will not
start, perform troubleshooting procedures in table 3-1.
