Starter Motor: Testing and Inspection

INSPECTION

ARMATURE INSPECTION AND TEST
1. Remove the starter.
2. Disassemble the starter as shown at the beginning of this procedure.
3. Inspect the armature for wear or damage from contact with the permanent magnet. If there is wear or damage, replace the armature.




4. Check the commutator (A) surface. If the surface is dirty or burnt, resurface with emery cloth or a lathe within the following specifications, or recondition with #500 or #600 sandpaper (B).




5. Measure the commutator (A) runout.
a. If the commutator runout is within the service limit, check the commutator for carbon dust or brass chips between the segments.
b. If the commutator run out is not within the service limit, replace the armature.

Commutator runout Standard (New): 0.02mm (0.0008in.) max Service limit: 0.05mm (0.0020in.)




6. If not within specification. replace the commutator.
7. Check for continuity between the segments of the commutator. If an open circuit exists between any segments, replace the armature.




8. Check with an ohmmeter that no continuity exists between the commutator (A) and armature coil core (B), and between the commutator and armature shaft (C). If continuity exists, replace the armature.





INSPECT STARTER BRUSH
Brushes that are worn out, or oil-soaked, should be replaced.





STARTER BRUSH HOLDER TEST
1. Check that there is no continuity between the (+) brush holder (A) and (-) brush holder (B). If there is no continuity, replace the brush holder assembly.




2. Pry back each brush spring (A) with a screwdriver, then position the brush (B) about halfway out of its holder, and release the spring to hold it there.




3. Install the armature in the housing, and install the brush holder. Next, pry back each brush spring again, and push the brush down until it seats against the commutator, then release the spring against the end of the brush.

NOTE:
To seat new brushes, slip a strip of #500 or #600 sandpaper, with the grit side up, between the commutator and each brush, and smoothly rotate the armature. The contact surface of the brushes will be sanded to the same contour as the commutator.





INSPECT OVERRUNNING CLUTCH
1. Slide the overrunning clutch along the shaft.
Replace it if does not slide smoothly.
2. Rotate the overrunning clutch both ways.
Does it lock in one direction and rotate smoothly in reverse? If it does not lock in either direction or it locks in both directions, replace it.




3. If the starter drive gear is worn or damaged, replace the overrunning clutch assembly. (the gear is not available separately).
Check the condition of the flywheel or torque converter ring gear if the starter drive gear teeth are damaged.