LINK AS 0875802 - Caterpillar

Do not use an impact wrench to operate the barring device. The use of an impact wrench will cause gear tooth failure.
Guards must be in place prior to operating barring device motor.Remove all hand tools prior to operating barring device motor.
Illustration 1 g00334420
Rear view of a barring device with an electric motor
Note: Prelube of the engine is required before the crankshaft is rotated for normal maintenance.The barring device provides a means for slowly turning the flywheel in order to service the engine. The barring device can also be used to prevent rotation of the crankshaft. When the barring device is in the engaged position, the engine starting system is disabled.When the barring device is not used, the barring device must be fully disengaged from the flywheel and secured in the disengaged position. Refer to the Service Manual for information on operation of the barring device.
Do not operate the engine starting motor until the barring group pinion gear is fully disengaged from the flywheel ring gear. Serious damage to the engine could result.
Ensure that the barring device is locked in the disengaged position.
Illustration 2 g00748157
Right side section view of a barring device without an electric motor
(1) Grease fitting
(2) Vent
Lubricate grease fitting (1) with MPGM until the grease is visible at vent (2).