Starter Motor: Testing and Inspection

TESTING






NOTE: These tests must be performed within 3 to 5 seconds to avoid burning out the coil.

1. DO PULL-IN TEST
a. Disconnect the field coil lead from terminal C.
b. Connect the battery to the magnetic switch as shown. Check that the clutch pinion gear moves outward.
If the clutch pinion gear does not move, replace the magnetic switch.




2. DO HOLD-IN TEST
While connected with the clutch pinion gear out, disconnect the negative (-) lead from terminal C. Check that the clutch pinion gear remains out.
If the clutch pinion gear returns inward, replace the magnetic switch.




3. INSPECT CLUTCH PINION GEAR RETURN
Disconnect the negative (-) lead from the switch body. Check that the clutch pinion gear returns inward.
If the clutch pinion gear does not return, replace the magnetic switch.




4. INSPECT CLUTCH PINION GEAR CLEARANCE
a. Connect the battery to the magnetic switch as shown.




b. Move the pinion gear toward the stop collar to remove slack and measure the clearance between the pinion gear end and starter housing.

Standard clearance: 1.0-5.0 mm (0.04-0.20 in.)




5. DO NO-LOAD PERFORMANCE TEST
a. Connect the field coil lead wire to terminal C. Make sure the lead is not grounded.
b. Connect the battery and ammeter to the starter as shown.
c. Check that the starter rotates smoothly and steadily with the clutch pinion gear moving out. Check that the ammeter reads the specified current.

Specified current: 90 A or less at 11.5 V

INSPECTION




1. INSPECT ARMATURE COIL COMMUTATOR FOR OPEN CIRCUIT
Using an ohmmeter, check that there is continuity between the segments of the commutator.
If there is no continuity between any segment, replace the armature.




2. INSPECT ARMATURE COIL COMMUTATOR FOR GROUND
Using an ohmmeter, check that there is no continuity between the commutator and armature coil core. If there is continuity, replace the armature.
3. INSPECT COMMUTATOR FOR DIRTY AND BURNT SURFACES
If the surface is dirty or burnt, correct with sandpaper (No.400) or a lathe.




4. INSPECT COMMUTATOR CIRCLE RUNOUT
a. Place the commutator on V-blocks.
b. Using a dial gauge, measure the circle runout.

Maximum circle runout: 0.05 mm (0.0020 in.)

If the circle runout is greater than maximum, correct it on a lathe.




5. INSPECT COMMUTATOR DIAMETER
Using vernier calipers, measure the commutator diameter.

Standard diameter: 28.0 mm (1.102 in.)
Minimum diameter: 27.0 mm (1.063 in.)

If the diameter is less than minimum, replace the armature.




6. INSPECT COMMUTATOR UNDERCUT DEPTH
Check that the undercut depth is clean and free of foreign materials. Smooth out the edge.

Standard undercut depth: 0.6 mm (0.024 in.)
Minimum undercut depth: 0.2 mm (0.008 in.)

If the undercut depth is less than minimum, correct it with a hacksaw blade.




7. INSPECT FIELD FRAME (FIELD COIL) FOR OPEN CIRCUIT
Using an ohmmeter, check that there is continuity between the lead wire and field coil brush lead.
If there is no continuity, replace the field frame.




8. INSPECT FIELD FRAME (FIELD COIL) GROUND
Check the field coil for ground.
Using an ohmmeter, check that there is no continuity between the field coil end and field frame.
If there is continuity, repair or replace the field frame.




9. INSPECT BRUSH LENGTH
Using vernier calipers, measure the brush length.

Standard length: 14.0 mm (0.551 in.)
Minimum length: 9.0 mm (0.354 in.)

If the length is less than minimum, replace the brush (field frame side) or brush holder, and dress with an emery cloth.




10. INSPECT BRUSH SPRINGS
Check the brush spring load.
Take the pull scale reading the instant the brush spring separates from the brush.

Spring installed load:
13.7 - 17.6 N (1.4 - 1.8 kgf, 3.1 - 4.0 lbf)

Minimum spring installed load:
8.8 N (0.9 kgf, 2.0 lbf)

If the installed load is not as specified, replace the brush springs.




11. INSPECT BRUSH HOLDER
Check the brush holder insulation.
Using an ohmmeter, check that there is no continuity between the positive (+) and negative (-) brush holders.
If there is continuity, repair or replace the brush holder.

12. INSPECT CLUTCH AND GEAR
a. Check the gear teeth on the planetary gear, internal gear and starter clutch for wear or damage.
If the gear is damaged, replace it.
If the starter clutch teeth are damaged, replace the starter clutch and also inspect the flywheel ring gear for wear or damage.




b. Check the starter clutch.
Rotate the clutch pinion gear clockwise and check that it turns freely. Try to rotate the clutch pinion gear counterclockwise and check that it locks.
If necessary, replace the starter clutch.




13. INSPECT MAGNETIC SWITCH
a. Check the plunger.
Push in the plunger and release it. Check that it returns quickly to its original position.
If necessary, replace the magnetic switch.




b. Check the pull-in coil for open circuit.
Using an ohmmeter, check that there is continuity between terminals 50 and C.
If there is no continuity, replace the magnetic switch.




c. Check the hold-in coil for open circuit.
Using an ohmmeter, check that there is continuity between terminal 50 and the switch body.
If there is no continuity, replace the magnetic switch.




14. INSPECT BEARING
a. Check the planetary carrier shaft.
Using a micrometer, measure the outer diameter of the surface in contact with the center bearing of the planetary carrier shaft.

Standard shaft diameter:
14.980 - 15.000 mm (0.5898 - 0.5906 in.)




b. Check the center bearing.
1. Using a caliper gauge, measure the inside diameter of the center bearing.

Center bearing inside diameter:
15.008 - 15.050 mm (0.5908 - 0.5925 in.)

2. Subtract the planetary carrier shaft diameter from the bearing inside diameter measurement.

Standard center bearing oil clearance:
0.01 - 0.06 mm (0.0004 - 0.0024 in.)

Maximum center bearing oil clearance:
0.2 mm (0.0078 in.)

If the clearance is greater than maximum, replace the planetary carrier shaft and center bearing.