RIDGID R851150 Operator's Manual page 16

OPERATION
TWO-SPEED GEAR TRAIN
See Figure 9.
The drill has a two-speed gear train designed for drilling or
driving at LO (1) or HI (2) speeds. A slide switch is located on
top of the drill to select either LO (1) or HI (2) speed. When
using drill in the LO (1) speed range, speed will decrease
and unit will have more power and torque. When using drill in
the HI (2) speed range, speed will increase and unit will have
less power and torque. Use LO (1) speed for high power
and torque applications and HI (2) speed for fast drilling or
driving applications.
NOTE: If you have difficulty changing from one gear range to
the other, turn the chuck by hand until the gears engage.
CAUTION:
Never change gears while the tool is running.
Failure to obey this caution could result in serious
damage to the drill.
MODE CHANGE RING
See Figure 10.
The mode change ring allows you to quickly switch from drill
mode to drive mode.
In general, drill mode should be used for drilling and other
heavy duty applications. Drive mode should be used for
driving screws. Hammer mode should be used for hammer
drilling.
TWO-SPEED GEAR
TRAIN (HI-LO)
HI
SPEED
HAMMER
MODE
DRIVE
MODE
DRILL MODE
(TORQUE ADJUSTMENT
NOT ACTIVE)
16
LOW
SPEED
1
2
MODE
CHANGE RING
Fig. 9
Fig. 10