Alternator: Testing and Inspection

INSPECTION




1. INSPECT GENERATOR BRUSH HOLDER ASSEMBLY
a. Using vernier calipers, measure the exposed brush length.

Standard exposed brush length: 10.5 mm (0.413 in.)
Minimum exposed brush length: 4.5 mm (0.177 in.)

If the exposed brush length is less than the minimum, replace the brush holder assembly.

2. INSPECT GENERATOR ROTOR ASSEMBLY




a. Check that the bearing is not rough or worn.

If necessary, replace the rotor assembly.




b. Check if the rotor has an open circuit.
1. Measure the resistance between the slip rings.

Resistance: 2.3 to 2.7 Ohms at 20 °C (68 °F)

If the resistance is not as specified, replace the generator rotor.




c. Check the rotor for ground.
1. Measure the resistance between the slip ring and rotor core.

Resistance: 1 M Ohm or higher

If the resistance is not as specified, replace the rotor assembly.

d. Check that the slip rings are not rough or scored.

If rough or scored, replace the rotor assembly.




e. Using vernier calipers, measure the slip ring diameter.

Standard diameter: 14.2 to 14.4 mm (0.559 to 0.567 in.)
Minimum diameter: 14.0 mm (0.551 in.)

If the diameter is less than the minimum, replace the rotor assembly.




3. INSPECT GENERATOR DRIVE END FRAME BEARING
a. Check that the bearing is not rough or worn.

If necessary, replace the bearing.

4. REMOVE GENERATOR DRIVE END FRAME BEARING




a. Remove the 4 screws and retainer plate.




b. Using SST and a wooden block, tap out the bearing

SST 09950-60010 (09951-00250), 09950-70010 (09951-07100)

5. INSTALL GENERATOR DRIVE END FRAME BEARING




a. Using SST and a press, press in a new bearing.

SST 09950-60010 (09951-00470), 09950-70010 (09951-07100)




b. Install the retainer plate with the 4 screws.

Torque: 2.3 N.m(23 kgf.cm, 20 in.lbf)