How to Repair a Starter Drive

When the starter spins, but the engine does not crank up the usual problem can be traced to the starter drive. The pinion gear on the drive may be broken and therefore require replacement. In some cases, if the starter drive is in bad shape, it should be replaced entirely.

Tools and Materials

  • Ratchet wrench and extension
  • Socket set
  • Jack
  • Jack stands
  • Replacements

Step 1 – Remove the Starter

The drive is connected to the starter, and any repairs on the drive require the removal of the starter first. To avoid electrocution during repairs, disconnect the negative battery cable. Use a jack to elevate the front end of the car. As soon as the car is elevated, put jack stands underneath the car in the corresponding jacking joints.

Disconnect the positive cable on the starter, using a ratchet. Detach the starter signal connector from the starter solenoid as well. The connector should be colored black. The connector can be easily pulled off using your hands. Locate the bolts securing the device to the engine block, and loosen them with a ratchet. Use an extension for extended reach if necessary. Remove the device from the engine. Be careful not to drop it. It can be very heavy.

Step 2 – Inspect the Starter Drive

Remove the front gear case, so that it detaches from the yoke housing. Remove the shift lever as well, without removing the armature. Shove the pinion stopper away from the armature, by pushing it a bit towards the rear cover. Remove the stopper clip, and the stopper itself. With the stopper removed, slide the starter driver away from the armature. Inspect the pinion gear for any sign of damage. Remove it from the assembly if it is worn out.

Purchase a replacement and slide it into the drive. Count the number of teeth in the gear, to ensure that the replacement purchased is correct. If not, take the original gear to the automotive shop during purchase. If the drive is still in good condition, keep in mind not to wash it with water or any other liquid that may dissolve its lubricants.

If the entire starter drive has incurred damage beyond repair, it is best to replace it entirely with a new one. Take the device to the automotive supply store and get a replacement.

Step 3 – Reinstall the Drive

Slide the device into the armature, and install the pinion stopper and clip. Reconnect the front gear case to the yoke housing, as well as the shift lever to the armature. Ensure that all the parts of the starter are correctly assembled. Secure it back to the engine, and tighten the bolts. Reconnect the positive cable on the starter, as well as the starter signal connector to the solenoid.

When everything is back in place, put the jack back, remove the stands and lower the car. Reconnect the negative battery cable, and test the engine to see if the issue has been solved. The engine should crank up as soon as it is turned on.