How to Rebuild a Starterby Contributor
Instead of shelling out a few hundred dollars for a rebuilt starter and installation from a mechanic, you can actually rebuild the starter yourself. Exact details may differ slightly depending on the year and model of your car, so check your owner's manual or installation guide. In general, however, you should be able to do the majority of the work on your own with some basic knowledge, as the process requires mostly cleaning.
Remove the Starter and Copper Contacts
Disconnect the negative cable from the battery. You can also disconnect the battery entirely, so you don't injure yourself as you remove the starter, but always remove the negative cable first.
Remove the starter. This may be the most difficult part of the process. Depending on the type of car you have, you may need to remove other parts to get to the starter. In some vehicles, you may need to work around (bend, remove) the brake line. Usually a heat shield covers the starter and is held in place by a 10 mm bolt.
Separate the field frame and armature from the starter housing. Generally you want to remove the 2 long bolts holding the 2 pieces of your starter together. Pull the frame up and off of the starter. The armature may actually come up with this, so be careful as you separate the pieces.
Remove the 3 screws holding the magnetic end cap onto terminal C of the starter. The screws will be in a triangular pattern. Take off the cap, revealing the plunger and copper contacts.
Pull the plunger straight out. There is a small spring on the end of the plunger that you should not lose.
Clean the plunger using a wire brush or sandpaper to smooth the underside of the copper ring on the top of the plunger. You may also replace the part if you wish.
Remove the nuts, washer and insulators that hold the L-shaped contacts in place. The contacts should be housed on either side of the hole where the plunger sits. If the contacts are merely corroded, you may be able to clean or sand the part, but in most cases you will need new copper contacts for your starter. The contacts come in a starter rebuild kit if you purchased one.
Install the Contacts and Starter
Install the new copper L-shaped contacts in the opposite manner from which you removed them. Basically, you should place one contact on each side of the starter and then use an insulator, washer and bolt to attach.
Put the cleaned or new plunger back into the cylinder. Don't forget the spring, which must be installed first. Basically, the plunger pushes against the spring to cause resistance.
Replace the cover, using the 3 bolts to secure.
Clean the Brushes and Replace the Starter
Remove the 2 screws or bolts holding the cap onto the field frame, which houses the brush holders. While terminal C had 3 bolts in a triangular pattern, this section only has 2 bolts. If you have already cleaned your contacts and plunger, this cap should be off and the armature may have come off when you removed the cap.
Clean the armature with a wire brush. The armature is a long, cylindrical piece that fits into the field frame. It may have a long rod coming from one end.
Look for the brush holder, which should be fairly easy to spot. The brushes do not look like an actual brush, but rather a block of carbon or other metal material. You should remove the brushes (some cars have 2 while others have 4) from the holder. You may need to use a screwdriver to release the spring clips.
Check that the brushes are long enough to connect to the armature. They should be a minimum of 10 mm. Use fine sandpaper or a wire brush to clean any grime from the brushes.
Replace the brushes in the holders.
Insert the armature into the field frame with the small coil facing the brushes. You may need to apply some fresh grease to the bearing surface, so that the armature turns freely.
Place the field frame cap over the brush holder and replace the 2 screws you removed earlier.
Turn the whole field frame assembly over and apply fresh grease to the bearing on that side of the armature. Install the field frame back into the starter housing.
Connect terminal C to the field house if you had to separate the 2 pieces and tighten any bolts. Place the starter back into the car.
- Most starters will list the part name and car company on the casing. This will help you order the correct parts. Starter rebuild kits are also available, but do not include a plunger, which you may need to buy to complete your rebuild.
- While you can clean the plunger, you may want to replace it, as the used plunger will wear out the new contacts more quickly than a new one.
- You should test the armature with a growler, which generates current and simulates the actual operation of the starter.