GMC 2001 Sierra 1500 Pickup Owner's Manual page 112

FIRST (1): Press the clutch pedal and shift into
FIRST (1). Then, slowly let up on the clutch pedal as
you press the accelerator pedal. Shift into FIRST (1)
only when the vehicle is below 5 mph (8 km/h). If you
try to shift down into FIRST (1) at excessive vehicle
speeds, the shift lever will not move into FIRST (1)
until vehicle speed is reduced.
SECOND (2): Press the clutch pedal and shift into
SECOND (2). Then, slowly let up on the clutch pedal
as you press the accelerator pedal.
You can shift into SECOND (2) when you're going less
than 20 mph (32 km/h). If you've come to a complete
stop and it's hard to shift into SECOND (2), put the shift
lever into NEUTRAL and let up on the clutch. Press the
clutch pedal back down. Then shift into SECOND (2).
If you try to downshift into SECOND (2) at excessive
vehicle speeds, the shift lever will not move into the
SECOND (2) position until the vehicle speed is reduced.
THIRD (3): Press the clutch pedal and shift into
THIRD (3). Then, slowly let up on the clutch pedal
as you press the accelerator pedal.
FOURTH (4) and FIFTH (5): Shift into the higher
forward gears the same way you do for THIRD (3).
Slowly let up on the clutch pedal as you press the
accelerator pedal.
To stop, let up on the accelerator pedal and press the brake
pedal. Just before the vehicle stops, press the clutch pedal
and the brake pedal, and shift to NEUTRAL.
NEUTRAL: Use this position when you start or idle
your engine.
REVERSE (R): To back up, first press down the clutch
pedal. Wait for the vehicle to stop moving and then, shift
into REVERSE (R). Let up on the clutch pedal slowly
while pressing the accelerator pedal.
NOTICE:
Shift to REVERSE (R) only after your vehicle is
stopped. Shifting to REVERSE (R) while your
vehicle is moving could damage your transmission.
Also, use REVERSE (R), along with the parking brake,
when turning off your engine and parking your vehicle.
2-29