Starter Motor: Testing and Inspection
INSPECTION1. INSPECT 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 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 it with sandpaper (No.400) or on 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 a vernier caliper, measure the commutator diameter.
Standard diameter: 30.0 mm(1.181 in.)
Minimum diameter: 29.0 mm (1.142 in.)
If the diameter is less than minimum, replace the armature.
6. INSPECT 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 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 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 a vernier caliper, measure the brush length.
Standard length: 15.5 mm (0.610 in.)
Minimum length: 10.0 mm (0.394 in.)
If the length is less than minimum, replace the brush holder and field frame.
10. INSPECT BRUSH SPRING LOAD
Take the pull scale reading the instant the brush spring separates from the brush.
Standard spring installed load: 17.6 - 23.5 N (1.8 - 2.4 kgf, 4.0 - 5.3 lbf)
Minimum spring installed load: 11.8 N (1.2 kgf, 2.6 lbf)
If the installed load is less than minimum, replace the brush springs.
11. INSPECT 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 GEAR TEETH
Check the gear teeth on the pinion gear, idler gear and clutch assembly for wear or damage.
If damaged, replace the gear or clutch assembly.
If damaged, also check the drive plate ring gear for wear or damage.
13. INSPECT CLUTCH PINION GEAR
Hold the starter clutch and rotate the pinion gear counterclockwise, and check that it turns freely. Try to rotate the pinion gear clockwise and check that it locks.
If necessary, replace the clutch assembly.
14. IF NECESSARY, REPLACE CLUTCH ASSEMBLY
A.Disassembly of starter housing and clutch assembly
a. Mount a brass bar in a vise, and install the starter housing and clutch assembly to the brass bar.
b. Push down the pinion gear.
c. Using a plastic-faced hammer, tap down the stop collar.
d. Using a screwdriver, pry out the snap ring.
e. Remove these parts:
1. Stop collar
2. Pinion gear
3. Compression spring
f. Push down the starter housing, and remove the spring retainer.
g. Disassemble these parts:
1. Starter housing
2. Starter clutch
3. Compression spring
4. Clutch shaft
B. Assemble starter housing and clutch assembly
a. Assemble these parts:
1. Starter housing
2. Starter clutch
3. Compression spring
4. Clutch shaft
b. Mount a brass bar in a vise, install the starter housing and clutch assembly to the brass bar.
c. Push down the starter housing, and install these parts:
1. Spring retainer
2. Compression spring
3. Pinion gear
4. Stop collar
d. Push down the pinion gear.
e. Using snap ring pliers, install a new snap ring.
f. Using pliers, compress the snap O-rings.
g. Check that the snap ring fits correctly.
h. Remove the starter housing and clutch assembly from the brass bar.
i. Using a plastic-faced hammer, tap the clutch shaft and install the stop collar onto the snap ring.
15. INSPECT REAR BEARINGS
Turn each bearing by hand while applying inward force.
If resistance is felt or the bearing sticks, replace the bearing.
16. IF NECESSARY, REPLACE REAR BEARING
a. Using SST remove the bearing.
SST 09286-46011
b. Using a press, press in a new front bearing.
17. INSPECT FRONT BEARING
Turn each bearing by hand while applying inward force.
If resistance is felt or the bearing sticks, replace the bearing.
18. IF NECESSARY, REPLACE FRONT BEARING
a. Using SST, remove the bearing.
SST 09280-46011
b. Using SST and a press, press in a new bearing.
NOTE: Be careful of the bearing installation direction.
SST 09820-00030
19. DO PULL-IN COIL OPEN CIRCUIT TEST
Using an ohmmeter check that there is continuity between terminals 50 and C.
If there is no continuity, check and replace the magnetic switch.
20. DO HOLD-IN COIL OPEN CIRCUIT TEST
Using an ohmmeter, check that there is continuity between terminal 50 and the switch body
If there is no continuity, replace the magnetic switch.
TEST
NOTE: These tests must be done within 3 to 5 seconds to avoid burning out the coil.
1. DO PULL-IN TEST
a. Disconnect the field coil lead wire from terminal C.
b. Connect the battery to the magnetic switch.
Check that the clutch pinion gear moves outward.
2. DO HOLD-IN TEST
With battery connected as above with the clutch pinion gear out, disconnect the negative (-) lead from terminal C.
Check that the pinion gear remains out.
3. INSPECT CLUTCH PINION GEAR RETURN
Disconnect the negative (-) lead from the switch body.
Check that the clutch pinion gear returns inward.
4. DO NO-LOAD PERFORMANCE TEST
a. Connect the battery and ammeter to the starter.
b. Check that the starter rotates smoothly and steadily with the pinion gear moving out. Check that the ammeter shows the specified current.
Specified current: 90 A or less at 11.5 V