Inspection and Repair

Repair or replace necessary parts if extreme wear or damage is found during inspection.

Armature




Measure the outer diameter of commutator, and replace with a new one if it is out of the limit.
Standard: 33.0 mm (1.30 in)
Limit: 32.0 mm (1.26 in)




Check for continuity between commutator and segment. Replace commutator it 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 armature core and commutator with a dial gauge. Repair or replace, if it exceeds the limit.

Armature
Standard: 0.05 mm (0.002 in) Max.
Limit: 0.10 mm (0.004 in)

Commutator
Standard: 0.05 mm (0.002 in) Max.
Limit: 0.10 mm (0.004 in)




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




Measure the depth of insulator in commutator. Repair, if it is below the limit.
Standard: 0.05 mm to 0.8 mm (0.02 in to 0.03 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: 16 mm (0.63 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).




Magnetic Switch
Check for continuity of shunt coil between terminals S and M.
Replace, if there is no continuity (i.e., coil is disconnected).




Continuity of Series Coil
Check for continuity between terminals S and M.
Replace, if there is no continuity (i.e., coil is disconnected).




Continuity of Contacts
With the plunger faced downward, push down the magnetic switch. In this state, check for continuity between terminals B and M. Replace, if there is no continuity (i.e., contacts are faulty).




Pinion
Check it the pinion rotates smoothly in drive direction by hand, or if it is locked when it is rotated in reverse. If not, replace the pinion.




Yoke Assembly
Check a magnet inside the yoke.
Replace the yoke assembly if it is broken.

Ball Bearing




Clamp the inner race of the ball bearing with your finger, and check for sticking or play when rotating the outer race.
Replace, if abnormality is found.
Measure inner diameter of bushing in the rear cover, and replace if it exceeds the limit.
Standard: 12.50 mm - 12.527 mm (0.492 in - 0.4932 in)




Limit: 12.60 mm (0.4961 in)




Measure inner diameter of bushing in the center bracket (P), and replace if it exceeds the limit.
Standard: 18.01 mm - 18.127 mm (0.7091 in - 0.7137 in)
Limit: 18.15 mm (0.7146 in)