you are describing one of the symptoms of something out of
round/balance.  normally the bearings or bearing surface in an
alternator.  with that kind of symptom i would turn it in as a core and
get a replacement rather than rebuilding that one.
jimt
On Tuesday, Oct 29, 2002, at 12:02 America/Denver, Mike Ray wrote:

> Howdy all, Before I get a new Alternator, can anybody make an educated
> guess what part is bad?
>
> It bench tests fine electrically. It was rebuilt 5 years ago w/ new
> bearings. At about 3K RPM, it vibrates (grumbles). You can hear it but
> not see it. When you free spin the shaft, there is no side-to-side
> play BUT there is forward to rear play in the shaft. Is it most
> likely...
>
> bearings, center shaft, or housing? I guess what's bad would decide if
> I get it rebuilt or replaced. Thanks all!
>
> Mikey
>
> `87 Westy Eeyore (big, blue, slow)
>
>
>
> ---------------------------------
> Do you Yahoo!?
> HotJobs - Search new jobs daily now
>