GEAR-COUPLING 9W9143 - Caterpillar

Illustration 1 g00322856
Manual barring group
(1) Shaft with gear and grease fitting
(2) Locking nut
(3) Knob
(4) Adapter The manual barring group allows an electrically driven motor to be used in order to turn the engine slowly. The manual barring group is used while service work is being performed.Use the following procedure in order to engage the manual barring group:
Do not use an impact wrench to operate the barring device. The use of an impact wrench will cause gear tooth failure.
Loosen locking nut (2).
If the barring group's knob is not pulled fully outward during engagement of the pinion and during disengagement of the pinion, the knob's shaft will damage the pinion shaft's O-ring seals. Make sure that the knob is pulled fully outward when you engage the pinion and when you disengage the pinion.
Pull knob (3) fully outward and press locking nut (2) until the nut is flush with the housing. Note: Locking nut (2) is part of the spring loaded pinion shaft. If the locking nut cannot become flush with the housing, the shaft gear is not meshed with the flywheel ring gear. Maintain inward pressure on the nut and carefully adjust adapter (4). Turn the adapter in a clockwise direction or a counterclockwise direction. The adjustment may require the adapter to be turned more than one revolution in any direction. Adjust the adapter until the locking nut can become flush with the housing.
After locking nut (2) is flush with the housing, release knob (3) and slowly remove hand pressure from the locking nut until the knob engages in the pinion shaft's slot. When the manual barring group is in the engaged position, the engine starting system is disabled.To turn the engine crankshaft, use the motor control. The manual barring group is directly coupled to an electric motor. The electric motor produces the torque that is required to turn the crankshaft in either direction.If only the engine crankshaft is turned, approximately 10 N m (7 lb ft) of torque is required. More torque is required if the flywheel ring gear is engaged with driven equipment.The engine crankshaft is locked in place when the pinion gear on shaft (1) is engaged with the flywheel ring gear.Use the following procedure in order to disengage the manual barring group:
Pull knob (3) fully outward and press locking nut (2) until the spring on shaft (1) moves the pinion to the disengaged position.
Make sure that the pinion gear is fully disengaged. Note: The pinion gear is fully disengaged when locking nut (2) passes by the housing.
After the pinion gear is fully disengaged, release knob (3).
Tighten locking nut (2) to a torque of 70 15 N m (50 11 lb ft). Note: If shaft (1) fails to fully disengage, rotate adapter (4) in either direction. Rotating the adapter in either direction reduces the side loading (friction) between the pinion gear and the flywheel ring gear.
Do not operate the engine starting motor until the barring group pinion gear is fully disengaged from the flywheel ring gear.