RING 7W2221 - Caterpillar

The following maintenance procedure for generator bearings should be followed at every major engine overhaul:
Remove the bearing bracket. Inspect the following items: bracket bore, bearing outer race and rolling elements. On standby power units, the bearing must be inspected and the grease must be replaced at three year intervals. The sleeve in the bearing bracket should be inspected for out of roundness, excessive wear, and a bracket step that is less than 0.0762 mm (0.0030 inch). If there is no sleeve in the bearing bracket, inspect the bore of the bearing bracket. The bearing should be inspected for damage to the outer race, severe fretting, and smoothness of operation. When possible, the bearing elements should be inspected. Some double shielded ball bearings prevent visual inspection of the elements of the bearing. Other double shielded ball bearings have a retaining ring. This retaining ring can be removed in order to allow access for a visual inspection of the elements of the bearing. On two-bearing generators, the front bearing can only be removed after the hub is removed. In order to remove the hub, cut off the hub with a saw. Do not use a torch to remove the hub. Do not pull on the hub. Pulling the hub will damage the shaft.Note: Bearings that are being removed for failure analysis should not be cut off with a torch.
All ball bearings should be cleaned. The cavity in the bracket should be repacked with 2S-3230 Grease. Pack the ball bearings (one-third to one-half of the volume of the cavity). Refer to Table 1. To reinstall the ball bearings, use an induction heater to heat the ball bearings to 107 °C (224.6 °F) for ten minutes. Mount the bearings on the shaft. To reinstall the hub, heat the hub to 400 °C (752.0 °F) for three hours. Mount the hub to the shaft.
Ensure that the tube of the grease gun is filled with grease.
Remove the bracket drain plug and operate the generator for one hour. This will allow the grease to expand. The expanding grease will force the excess grease from the cavity. When the excess grease is forced from the cavity, the internal pressure will be reduced. The generator should continue to operate until the grease stops purging.
Stop the engine. Install the bracket drain plug. Wipe off the excess grease.
For greasing intervals, follow the recommendations on the lubrication plate (if equipped) or refer to Maintenance Schedule, "Bearing - Lubricate". Whenever the bearings are greased, repeat Step 4. DO NOT MIX GREASES.
Table 1
Bearing Outside Diameter
mm (inch) Bearing Inside Diameter
mm (inch) Part Number Generator Frame Size Bearing Bore in Bracket
mm (inch) Bearing Shield (Type) Bearing
Cavity
Grease
mL (oz) Rotor
Shaft
Diameter
mm (inch)
225 mm (8.8582 inch) 105 mm (4.1338 inch) 6V-0410 680(1) 225.003 mm (8.8584 inch)
to
225.034 mm (8.8596 inch) Single 139.12 mL (4.7 oz)
to
230.88 mL (7.8 oz) 105.029 mm (4.1350 inch)
to
105.034 mm (4.1352 inch)
225 mm (8.8582 inch) 105 mm (4.1338 inch) 108-1760 680(1) 225.003 mm (8.8584 inch)
to
225.034 mm (8.8596