Do your refurbished alternators keep dying?

[jslew]

I've got a 91 NA. When the alternator died I did some research & learned most reman jobs dont last long. So i went to the dealer & he said their reman guys in mexico were the best & ripped me off $300. That alt lasted about 30 hours. I went to rock auto & found an oem hitachi refurbished in mexico for $120. It was from the same guys in mexico as the one from the dealer. It lasted approx 30 hours.

I took the first one to an alternator shop. He tested it - 0V.
He took it apart, and immediately noticed the brushes were not centered on the slip rings. One of the brushes was actually off the side of the slip ring so far that it created a lip on the brush. The lip of the brush was contacting the area between the slip rings. I forgot to ask if it was grounding, or if the lip was keeping the brush from contacting the slip ring, but either way that was the problem. The plant had pushed the slip rings on too far.

He said that alternator was only used for 6 years (or was it 3?), and only for 300zx, so its pretty rare. Said that the plant in Mexico may be the only guys redoing them. Apparently the plants in mexico are known for being very consistent - but incorrectly calibrated - or maybe just worn out. Long story short, he moved the slip rings, and it worked like a charm - 14.8V.

So, if you buy a refurbished alternator that was done in Mexico, you better pull it apart and check your brushes. They may be pushed on .0065" too far. Mine was a hitachi, but i would imagine if there's only one place redoing them, any other brand might have the same issue.

[DCaff300ZX]

Welcome!
That is good info and new info to me, so thanks for sharing. It really does not surprise me anymore about these types of things, which are far too common in nearly all areas of manufacturing these days due to how often custom-sized and -configured components are used and in short-run applications.

Just for the record though another major issue with the Z32 and alternators is the power steering reservoir above the alternator leaking fluid onto/into the alternator, often causing replaced alternators to fail prematurely.

[jslew]

...power steering reservoir above the alternator leaking fluid onto/into the alternator, often causing replaced alternators to fail prematurely.

I question their engineering every time i look at an engine with the alternator on top!!! Everything else was done so well!

[DCaff300ZX]

Agreed, and wait until you get to play with the connectors...they had some IMO nearly criminal decisions made along with all of the great ones in making this beast work back in the day, and unfortunately we get to fix or replace those systems in order to get long term usage out of the otherwise great package.
An all-too-common situation these days as we have made cars FAR more complicated in our efforts to make them "better" in nearly all ways, and it shows up in many other areas of life as well.