How to Repair an Alternator
Alternator repairs to a vehicle can be a rather difficult task, especially for individuals who are not very skilled in the area of auto mechanics. However, if you do have a certain level of skill and are up for the challenge, the job is not impossible.
- Look at the "clock" position of the alternator and make note of it. This will be the front to back way the alternator is housed within the engine. You'll need to refer back to this information later so keep it handy.
- Remove the drive end frame assembly from the ring end frame. You can do so by removing the three thru bolts. However, you'll want to leave the stator in the rear housing area. Take the drive end frame from the rotor and pout the rotor in a hex wrench to take off the shaft nut.
- Take apart the slip ring end frame. Press the cover pins out and remove the cover. Slice the leads that are attached to the rectifier bridge terminals and remove the stator. Poke the baffle pins out and remove the baffle.
- Take off all the fasteners and raise the brush holder, rectifier bridge and the regulator from the end frame.
- Make any necessary repairs to the rectifier bridge. Connect an ohmmeter at a low scale to the heat sink from the bridge terminals and reverse the connections. If each of them are reading the same, replace the rectifier bridge.
- Clean off the brush holder using a soft, dry cloth. If the brushes are badly damaged, replace the entire brush component.
- Turn the rotor by hand to clean the slip rings. Push a fine polishing cloth up against the rings while it is turning.
- Press on the outside area of the bearing assembly to replace it. You'll need to push until it easily slips to the bottom of the frame. Solder the connectors back together as they originally were.
- To replace the cleaned brushes, put them in the holder and pin them in. You'll need to use some sort of electrical contact transfer grease on the end frame casting just under the rectifier bridge to help dissipate the heat.
- Reattach all the parts. Press down on both the inner and outer race of the slip ring end bearing, this will connect the end frames. Replace the thru bolts that you originally removed.