The following VFAQ has disappeared from the original site, so I have pulled down a copy from the WaybackMachine.

Many times not all graphics are stored by the WaybackMachine, so if there are graphics missing from the following VFAQ, please don't email me about them (unless you are emailing me to tell me you have a copy of the missing graphic you can send me).

If you know the original author of this VFAQ, and have their contact info, please have them email me if they have any missing info to add, have the VFAQ at another site I could not find, or wish to have it removed from my site.


This VFAQ used to be located at http://myzero.com/electrical/alt.html



Alternator Repair

Jump Links: Tools, Part List, Alternator Removal Procedure, Brush Removal Procedure, Bearing Removal Procedure


After I changed the timing belt on my '91 GST, I started getting a very bad belt squeal. I narrowed it down to the crankshaft -> water pump -> alternator belt. I replaced the belt, adjusted tension, used factory belts... no change. One weekend I started the car and let it run for about 10 seconds (squealing all the time). I then touched each of the pulleys: crankshaft -- cool, water pump -- cool, alternator -- hotter the hell! That told me that there is something has gone bad on/in the alternator. More than likely one/both of the bearings. So I replaced them along with the brushes since I was in there. Here is the procedure I used to do all of that, so you may need only a portion of this procedure if you're not replacing what I did.

Tools Needed

Alternator Removal
ratchet
sockets (10mm, 12mm, 14mm)
screwdriver
Bearing Removal
Screwdriver (flat head & philips)
Hammer
Ratchet Extension
Impact Wrench (22mm socket)
Bearing Seperator (for rear bearing only)
2-arm gear puller (for use with bearing seperator)
Brush Removal
soldering iron
desoldering pump
piece of chicken wire (or small Allen wrench)

Parts List
MD 611566; Alternator Brush; $4.79/ea; Need 2
MD 611397; Front Alternator Bearing; $21.24
MD 611928; Rear Alternator Bearing; $13.45

Alternator Removal Procedure
  1. Disconnect the electrical connector going to the A/C Fan Motor
  2. Unscrew the 3-10mm bolts holding on the A/C Fan Motor (2 up top, 1 on bottom). Start with the bottom bolt, then do the top 2 (see picture).
  3. Remove the lower splash shield (12mm bolts)
  4. Remove all the accessory belts
  5. Remove both water pump pulleys
  6. Remove the electrical connectors going to the alternator. There's 1 plug-type connector and another that's a wire with a loop held on by a nut.
  7. Remove the upper alternator brace (12mm bolts)
  8. Remove the bottom alternator bolt nut (12mm; see picture)
  9. Push the bolt out through to the other side (see picture)
  10. Remove the alternator. You'll likely have to rock it back and forth to get it to come out. Pull alternator out through the top.

Brush Removal Procedure

  1. Remove the 4 bolts holding the alternator casing together (8mm; see picture). Don't worry it takes a lot more effort to get the case apart.
  2. Take a screwdriver and separate the stator (ridged copper looking thing between the 2 halves of the alternator) from the FRONT (pulley side) casing. See picture. You will damage the alternator if you separate the stator from the back casing first.
  3. Place aside front casing/alternator assembly. We only need the back casing/stator portion for the rest of this procedure.
  4. On the back of the casing remove the nut/plastic washer that connected to the wire/loop electrical connection in the Alternator Removal Step 6. See picture
  5. Turn the casing over and look at the regulator/brush portion. Remove the 3 screws holding the electrical assembly on. See picture.
  6. You can now remove the status along with the electrical assembly from the rear casing. See picture.
  7. Rotate the light brown cover over the 2 solder points for the brushes. Then the small yellow-ish piece covering the holes the brush leads come out. See picture.
  8. Remove the solder on the end of the leads.
  9. Remove the brushes through the shaft side of the assembly
  10. Put a new rush in (only 1 at this time)
  11. You will see a hole from the front of the assembly through to the back. Be sure that you can push the brush up and see all the way through that hole. If you can't, remove the brush and rotate it 180 degrees and try again. This time you should see all the way through.
  12. Repeat above for the second brush.
  13. Solder the end of the brush wire to the contact where the old brush was. Be careful: Don't trim any of the brush wire off. The brush needs to be able to slide down as it wears so don't make the leads tight.
  14. When complete with both brushes, push the brushed up and fit a piece of wire of small allen wrench through the hole in the brush assembly. This allows you to put the alternator back together and not have the brushes in the way of the shaft. When the alternator is totally back together, you remove the wire or wrench to engage the brushes.

Bearing Removal Procedure

  1. Repeat Steps 1 and 2 in the Brush Removal Procedure
  2. Take the impact wrench (22mm) and remove the nut holding on the alternator pulley and remove the pulley.
  3. Unscrew the 4 bolts holding on the bearing retainer. See picture
  4. Take a hammer and socket extension and bang the shaft out of the front casing. See picture.
  5. Now use the socket extension to remove the front bearing from its socket. See picture.
  6. Put the bearing seperator and 2-jaw gear puller in place. See picture.
  7. Seperate the rear bearing
  8. Replace the bearings
 

This document can be reprinted for personal use or reference for your mechanic(s) with no prior permission needed. It can be linked to directly, as long as you have a link to the main page of http://www.myzero.com, though linking to the main page instead is preferred. This document can NOT be reprinted for profit/resale/redistribution of ANY type without expressed WRITTEN permission from me in advance. Bulk copying of this document onto your web site without prior permission will not be tolerated, link to it instead.

Copyright 1999, Brad Bauer