COVER 7B7770 - 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 3 year intervals. The sleeve for 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 for the bearing bracket, inspect the bore for 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 ball bearings. 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 ball bearings. 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. Pulling the hub will damage the shaft.Note: Bearings that are being removed for failure analysis should not be cut off with a torch.
Spherical Roller Bearing should be cleaned and repacked with 108-8611 Grease. Pack the bearing and pack the cavity (one-third to one-half of the volume of the cavity). The bearing should be filled with 88.8 mL (3 oz) to 118.4 mL (4 oz) of grease. The cavity should be filled with 118.4 mL (4 oz) to 148.0 mL (5 oz) of grease. Refer to Table 1.
All ball bearings should be cleaned. The cavity of the bracket should be repacked with 2S-3230 Grease. Pack the bearings (one-third to one-half of the volume of the cavity). Refer to Table 1. To reinstall bearings, heat the bearings to 107 °C (224.6 °F) for 10 minutes. Mount the bearings on the shaft. To reinstall the hub, heat the hub to 400 °C (752.0 °F) for 3 hours. Mount the hub to the shaft.
Ensure that the tube that supplies grease to the bearing is filled with grease.
Remove the bracket drain plug and operate the generator for 1 hour to 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, "Generator Bearing - Lubricate". Whenever the bearings are greased, repeat Step 5. 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)
100.000 mm (3.9370 inch) 45.000 mm (1.7717 inch) 5P-1977 All 360 100.000 mm (3.9370 inch)
to
100.025 mm