NUT 2981609 - Caterpillar

Exciter Drive Pulley Removal And Installation
The pulley (3) is held to shaft (2) by key (5). The retainer ring (6) is held to the pulley by key (4). The pulley is held tight on the shaft by the clamping action of the retainer ring.
PREPARING TO REMOVE PULLEY
1. Bolt.1. Remove the bolts (1) that hold the retainer ring (6) to the pulley (3).2. Use the same bolts as puller screws and force the retainer ring from the shaft (2) and pulley.3. Remove the pulley from the shaft.
PULLEY REMOVAL
2. Shaft. 3. Pulley. 4. Key. 5. Key. 6. Retainer ring.4. Install in the reverse order of removal. Align the exciter pulley with the generator pulley by moving the pulley before the bolts (1) have been tightened.