Isuzu Cars and Trucks 1981-1991

Starter

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REMOVAL AND INSTALLATION
4-Cylinder Engines
  1. Disconnect the negative battery cable.
  2.  
  3. If equipped, it may be necessary to disconnect and remove the EGR pipe.
  4.  
  5. Disconnect and label the starter wiring at the starter.
  6.  
  7. Remove the starter-to-engine bolts and the starter from the vehicle.
  8.  

To install:

  1. Installation the starter to the engine.
  2.  
  3. Connect the electrical connectors to the starter.
  4.  
  5. If the EGR pipe was removed, install it.
  6.  
  7. Connect the negative battery cable.
  8.  



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Fig. Starter motor removal 4-cylinder engines

V6 Engine
  1. Disconnect the negative battery cable.
  2.  
  3. Raise and safely support the vehicle.
  4.  
  5. Label and disconnect the electrical connectors from the starter.
  6.  
  7. Remove the starter-to-engine mounting bolts.
  8.  
  9. Lower the starter from the engine. If any shims are present, keep them for reinstallation purposes.
  10.  

To install:

  1. Install the starter and shims, if equipped, to the engine. Torque the bolts to 30 ft. lbs. (40 Nm).
  2.  
  3. Reconnect the electrical connectors to the starter.
  4.  
  5. Lower the vehicle.
  6.  
  7. Connect the negative battery cable.
  8.  



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Fig. Starter motor removal V6 engine

SOLENOID REPLACEMENT
  1. Disconnect the negative battery cable.
  2.  
  3. Remove the starter motor from the vehicle.
  4.  
  5. Disconnect the solenoid-to-starter lead wire.
  6.  
  7. Remove the solenoid mounting bolts and solenoid. Pull out the torsion spring of the solenoid switch, if so equipped. On some models, it may be necessary to remove the starter assembly through bolts from the yoke to remove the solenoid.
  8.  

To install:

  1. Install the solenoid with any adjustment shims.
  2.  
  3. Torque the bolts to 15 ft. lbs. (20 Nm).
  4.  
  5. Connect the starter-to-solenoid electrical lead.
  6.  
  7. Install the starter through bolts if removed.
  8.  
  9. Install the starter motor with an shims, connect the wiring and battery cable.
  10.  
  11. Check for proper operation.
  12.  

OVERHAUL
Non-Reduction Type
DISASSEMBLY AND ASSEMBLY
  1. Position the starter in a soft jawed vise. Disconnect the field coil wire from the solenoid terminal.
  2.  
  3. Remove the solenoid mounting screws and work the solenoid from the shift fork. Remove the bearing cover, the armature shaft lock, the washer, the spring and the seal.
  4.  
  5. Remove the commutator end frame cover through bolts, the cover, the brushes and the brush plate.
  6.  
  7. Slide the field frame from over the armature. Remove the shift lever pivot bolt, the rubber gasket and the metal plate.
  8.  
  9. Remove the armature assembly and the shift lever from the drive end housing. Press the stop collar from the snapring, then remove the snapring, the stop collar and the clutch assembly.
  10.  
  11. If the brushes are worn more than 1 / 2 the length of new brushes or are oil-soaked, should be replaced; the new brushes are 16mm (0.630 in.) long.
  12.  
  13. Do not immerse the starter clutch unit in cleaning solvent as the solvent will wash the lubricant from the clutch. Place the drive unit on the armature shaft, then, while holding the armature, rotate the pinion.
  14.  


NOTE
The drive pinion should rotate smoothly in one direction only. The pinion may not rotate easily but as long as it rotates smoothly it is in good condition. If the clutch unit does not function properly or if the pinion is worn, chipped or burred, replace the unit.



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Fig. Exploded view of the non-reduction-type starter motor 4-cylinder engine



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Fig. Exploded view of the non-reduction-type starter motor V6 engine

To Assemble:

  1. Lubricate the armature shaft and splines with lubricant.
  2.  
  3. Install the clutch, the stop collar, the lock ring and the shift fork onto the armature.
  4.  
  5. Install the armature assembly into the drive end housing.
  6.  
  7. Install the field frame housing over the armature and onto the drive end housing.
  8.  
  9. Position the brushes into the brush holder and position the brush holder over the armature's commutator.
  10.  
  11. Install the commutator end housing and the through bolts.
  12.  
  13. Install the cap end gasket, the armature brake spring, the armature plate and the commutator end cap.
  14.  

Reduction Gear Type
DISASSEMBLY AND ASSEMBLY
  1. Position the starter in a soft jawed vise. Remove the nut and disconnect the motor wire from the magnetic switch terminal.
  2.  
  3. Remove the through bolts and pull the field frame (with the armature) from the magnetic switch assembly.
  4.  
  5. Remove the starter housing to magnetic switch assembly bolts and separate the housing from the assembly. Remove the pinion gear, the pinion retainer/bearings and the clutch assembly.
  6.  
  7. Using a magnetic finger, remove the spring and the steel ball from the hole in the clutch assembly shaft. Remove the field frame end cover.
  8.  
  9. Using a small pry bar, separate the brush springs, then remove the brushes from the brush holder and pull the brush holder from the field frame.
  10.  
  11. Remove the armature from the field frame. Using an ohmmeter, make sure there is no continuity between the commutator and the armature coil core. If there is continuity, replace the armature.
  12.  
  13. Using an ohmmeter, check for continuity between the commutator segments. If there is no continuity between any of the segments, replace the armature.
  14.  
  15. If the commutator is dirty, burnt or the runout exceeds 0.05mm (0.002 in.), use a lathe to reface the surface; do not machine the diameter to less than 29mm (1.140 in.) diameter.
  16.  
  17. Using an ohmmeter, make sure there is continuity between the lead wire and the brush lead of the field coil. If there is no continuity, replace the field frame.
  18.  
  19. Using an ohmmeter, make sure there is no continuity between the field coil and the field frame. If there is continuity, replace the field frame.
  20.  
  21. If the brush length is less than 10mm (0.394 in.), replace the brush and dress with emery cloth.
  22.  
  23. Check the gear teeth for wear or damage, if damaged, replace them. Turn the clutch assembly pinion clockwise and make sure it rotates freely, try to turn the pinion counterclockwise and make sure it locks. If the pinion does not respond correctly, replace it.
  24.  
  25. While applying inward force on the bearings, turn each by hand; if resistance or sticking is noticed, replace the bearings. To replace the bearings, use the tool 0928646011 or equivalent, to pull the bearing(s) from the armature shaft. Using the tool 0928576010 or equivalent, and an arbor press, press the new bearing(s) onto the armature shaft.
  26.  
  27. Using an ohmmeter, check for continuity between the grounded terminal and the insulated terminal, then between the grounded terminal and the housing. If there is no continuity in either case, replace the magnetic switch assembly.
  28.  



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Fig. Exploded view of the reduction gear-type starter motor

To Assemble:

  1. Lubricate the gears, the shafts and bearings with high temperature grease.
  2.  
  3. Install the over-running clutch, the pinion and the retainers with the rollers into the housing.
  4.  
  5. Install the spring to the magnetic switch and assembly the housing and the magnetic switch.
  6.  
  7. Install the brushes into the brush holder; make sure the positive brush leads are not grounded.
  8.  
  9. Install the rear end frame to the yoke, engage the tab with the wire grommet and install the cover.
  10.  
  11. Install the yoke to the magnetic switch, engage the tab on the yoke with the magnetic switch notch.
  12.  
  13. To complete the installation, reverse the removal procedures.
  14.  

DIAGNOSIS


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Fig. V6 starter motor circuit



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Fig. Diagnosis chart 1 V6 engine starter, others similar



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Fig. Diagnosis chart 2



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Fig. Diagnosis chart 3



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Fig. Diagnosis chart 4



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Fig. Troubleshooting basic starting system problems

 
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