Inspection and Repair

Armature




Measure the outer diameter of commutator, and replace with a new one if it is out of the limit.

Standard: 30 mm (1.1811 in)

Limit: 29 mm (1.1417 in)




Check for continuity between segment and segment on the commutator. Replace commutator if there is no continuity (i.e., disconnected).




Check for continuity between commutator and shaft. Also, check for continuity between commutator and armature core, armature core and shaft. Replace commutator if there is continuity (i.e., internally grounded).




Measure runout of the commutator with a dial gauge. Repair or replace, if it exceeds the limit.

Limit: 0.4 mm (0.0157 in)




Polish the commutator surface with sandpaper #500 to #600 if it is rough.




Measure the depth of insulator in commutator. Replace, if it is below the limit.

Standard: 0.45 mm to 0.75 mm (0.0177 in to 0.0295 in)

Limit: 0.2 mm (0.008 in)

Brush




Measure the length of brush.

Replace with a new one, if it is below the limit.

Standard: 15 mm (0.5906 in)

Limit: 11 mm (0.43 in)

Brush Holder




Check for continuity between brush holder (+) (4) and base (-). Replace, if there is continuity (i.e., insulation is broken).

Brush Spring
Use spring balancer to measure the spring setting force when remove the spring from the brush.

Standard: 17.65-23.54 N (38.9-51.9 lb)

Limit: 11.77 N (25.9 lb)

Magnetic Switch

Temporarily connect the magnetic switch between the overrunning clutch and housing.

Perform the steps described below in 3 to 5 seconds.




1. Pull in test

Connect the ground (-) to terminal C and magnetic switch body.

Verify that the pinion pulls out when the battery (+) pole is connected to terminal 50.




2. Hold in test

Observe that the pinion stays when the lead wire is disconnected from terminal C.




3. Return test

Connect the ground (-) to terminal 50 and magnetic switch body.

Verify that the pinion pulls out when the battery (+) pole is connected to terminal C and the pinion pulls away when the lead wire is disconnected from terminal 50.

Field Coil




1. Check for continuity between the end of the field coil and yoke body.

Replace the field coil, if there is continuity.




2. Check continuity between the lead wire of terminal C and brush.

Replace the yoke assembly, if there is no continuity.

Overrunning Clutch




1. Visual check for excessive wear or damage.

2. Test the pinion rotation, it must rotate smoothly when rotated clockwise and it shouldn't rotate when turned counterclockwise.

Bearing




1. Inspect excessive wear or damage.

Replace the bearing if an abnormal noise is heard under normal operating condition.