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Got any tricks for opening an Alternator?

ttabyss ยท 2020-03-22 14:59

The alternator came out of a 1986 Ford Superior pumper fire truck. The engine was made by Caterpillar. (see the attached pictures) After sitting in a field for a winter, the alternator won't turn over any more. It isn't completely seize up, I can turn the shaft fairly easily with an impact wrench but not by hand. Our local alternator shop won't touch it because it was custom made for fire trucks. They said something about the wiring on it was different and they can't repair or replace it. The 4 bolts that hold the halves together came out ok, but the two halves won't separate - maybe the shaft is stuck tight at both ends. Soaked it in diesel for a couple of months but it didn't free up any. So, I can turn the shaft a bit with an impact wrench but it doesn't loosen up. So, if you have a good idea to get it turning again I'd appreciate it. Cheers.

Replies5
  1. #1Truck Shop2020-03-22 15:14

    Leece Neville built the same basic alternator as Motorola, The Leece Neville equivalent is part #JHO-555 or you can also install a Delco #8600136 28SI or 36SI . You would be money ahead to up-grade it to a more common unit.

  2. #2Delmer2020-03-22 15:38

    If you're still determined to get this apart for whatever reason, the bearing is locked up, turning it with the impact is probably spinning the bearing in the housing, or spinning the bearing on the shaft. I'd pull the stuff off the back so you can see the bearing, might even be a plain bushing like on little alternators, then carefully heat the back housing just enough, the aluminum will expand more than the steel so hopefully that will make it a little easier to get apart. Use chisels, prybars, whatever it takes to get it apart. Pry the tabs apart, don't pry on the steel laminations in the middle, or use more care on the steel laminations.

  3. #3Coaldust2020-03-22 19:42

    I agree with Truck Shop. You can purchase a brand-new 160 amp Leece-Neville 110-555JHO for $175 from Amazon with free shipping. You'll spend more in time, frustration and resources to fix your old one. Auto- electric guys call those triple nickels. One of the most popular alternators.

  4. #4ttabyss2020-03-22 23:48

    Hey guys... Thanks!! That will do the trick. I will try to source a Leece-Neville locally. Amazon.ca carries it, however up here it is $425 + $100 shipping. Ouch! The 3 center poles are located differently. Where could I find info on mapping the wires from the Motorola to the Leece-Neville? ...and, thanks again! Cheers.

  5. #5Coaldust2020-03-23 01:42

    You won't have to worry about the two wires on the Voltage regulator because the new alternator will already have the wires connected. Like in this diagram I uploaded. That leaves you with the small terminal on the bottom of your picture. That small single terminal is the stator center tap. It was used in the old-days to send a rpm signal to a tachometer and other things. Often referred to as an "R terminal". Anyways, your new alternator will have three taps on it. Use the center one. The B+ wire and ground are self- explanatory.