Engine/Transmission (1994 - 1998) Alternator Rebuild Difficulty

[EBansberg]

I'm trying to rebuild the alternator but the instructions from the rebuild kit (geno's) leave a little to be desired. I'm attempting to separate the front from the back and the instructions say to gently tap them apart. I've been tapping them apart and used some screwdrivers to try to persuade them some but it still seems like it's not going as easily as it "should". They have a small gap but don't want to go any further. I don't want to break anything. Is there a screw or nut that I could've missed?



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[hdm48]

As long as the brushes and all the bolts/screws are out, it should be free to come apart.

Do you have a dead blow hammer?

Hold the unit so the shaft is pointing up, hold the unit by the upper half and with something soft under it to catch it, tap the shaft and it will fall apart.

Plan on replacing the bearings because anytime you shock load a bearing it will ruin it/them.

 

[hsmith]

REMOVE THE SCREWS FROM THE FIELD COILS FIRST. That would be the four that protrude thru the rear case from the side.

 

[EBansberg]

I'll look into removing the brushes first. The screws from the coils have been removed, I posted a picture but doesn't appear to be showing up. The instructions don't say to remove the brushes first but I'll do that, it's worth a try.

 

[JJanetka]

Mine was so corroded together that it took alot of coaxing before it would come apart. Like hdm48 said I would replace the bearings as well.

 

[EBansberg]

I ended up having to whack on the shaft with the deadblow hammer and it eventually came apart. I was planning to replace the bearings anyway but had to make sure I hadn't missed anything that would've held it together causing a "dumb me" moment. Everything is back together and it no longer squeals making me embarrassed to drive it.

 

[DieselDoghouse]

Before you wrap the job up - and because there have been so many alternator posts - if you can get an oscilloscope or someone has a computer that will analyze waveforms - I would tap into the alternator output looking for steady, continuous peaks - a gap in these "teeth" of the waveform would indicate at least one of the 6 diodes is bad and the rebuild isn't done. This can be a leading cause of rebuild failure even if done 'professionally'.

 

[WilsonF]

After putting brushes and bearing in mine it still would not charge, found that the diode pack was bad, replaced it and I was on my way.



Floyd

 

[DieselDoghouse]

What WilsonF said. Remember an alternator is a boat with 3 oarsmen (windings) and 6 paddles (diodes). If one of those oars ain't in the water (bad diode) then someone's smacking someone else with the paddle and the boat she don't go so well. (OK, OK I'm good at bad analogies)

 

[EBansberg]

I didn't have the ability to test it at the time and the main reason for rebuild was noise which was eliminated. I guess I know what to check now though if it stops charging. Thanks for everyone's input and experience

 

[SMorneau]

I had the same problem separating my alternator halves. I finally removed the screws thru the back that hold the rear bearing plate to the back half and pulled the back free. Mine was hung on the bearing. Then I ground a cheap 3 jaw puller to fit under the plate and pull it free. In hind site, I think I could have easily made a puller to pull it apart by separating the bearing from the bearing plate.

That said, the slip rings were well worn and I beat on mine so badly I felt bad enough about it to get a new one from Rockauto, nice price for the correct alternator. The first one lasted to about 290k miles so what the heck.