jim beam > wrote in
news

>
> if you "clean" the ring with emery, does it go smooth or does it stay
> rough?


On careful inspection, it looks like the bad patch (the part I showed in
the photo) only covers about 40-45 degrees of rotation. Past that, the
ring is pretty good, close to the appearance of the other ring. The
lathe-bit marks are nice and even all over.

Crocus cloth removes the black carbon deposits, showing even lathe marks
all over except within the bad patch.

To see what was happening within the bad patch I had to inspect with a
very bright light and a special magnifying glass similar to a jeweler's
loupe. The copper there definitely looks rough. The lines left by the
lathe bit are not smooth and even, but almost look randomly peened-over,
as though they'd been bead-blasted...but ONLY within the brush contact
area. Crocus cloth changes the apparent color, but the roughness
remains.

I wonder what happened within the rough patch that did not happen
outside of it?




> maybe the rings are "loose" sinter cores with a thin solid
> skin - and the skin's worn through.



Maybe. It's hard to tell. The rings consist of machined copper sleeves,
maybe 20-thou thick, riding on a thick plastic sleeve that's pressed (or
molded) on to an iron center bar.

I think it's just plain copper tubing, but your notion would explain the
roughness only being in the brush contact area.



> that would make brush replacement
> futile and keep a purchaser of this remanufactured alternator keep
> returning for new ones, hopefully outside of the warranty period.


I am certain that's their goal.

Other than speed of assembly and total absence of quality control, how
else can they sell these things so cheaply?



> what's the warranty and what's your mileage?


The warranty was one year, no mileage given. I average about 20K miles
per year these days, so the first aftermarket alternator lasted me about
18K (eleven months) and the other about 8K (five months).


--
Tegger

The Unofficial Honda/Acura FAQ
www.tegger.com/hondafaq/