Alternator screeching when under load

Shawn Manny shawn.manny at
Thu Dec 30 13:04:34 EST 2004

sounds like bearings to me, mine is strating to do this as well,
although I haven't noticed if its under load only or not...its real

On Thu, 30 Dec 2004 12:57:02 US/Eastern, radek at <radek at> wrote:
> Hello group, need your help.
> My 88 90Q has been doing this for some time now.  When the electrical load increases (like
> having the
> headlights on and switching on defrost) the alternator would start making the most awful,
> high-pitched
> screeching noise and stop charging (voltmeter drops from 14V to 12V or so).  First, I
> suspected the belt
> slipping but tightening it would not solve the problem.  Next, I suspected high electrical
> resistance so I
> took out the alternator, removed the voltage regulator, checked the brushes and cleaned
> all the
> contacts.  Still no help.  Yesterday the screeeching got worse and on my way back from
> work the belt
> broke.
> I know it looks like the belt is slipping but I don't think this is the case.  It is
> definitely moving.  The
> sound seems to be coming from inside the alternator.  Bearings?  Old age?  Time for
> rebuild?  I'm
> planning to take the alternator apart on the weekend.  How easy/difficult would it be to
> replace the
> bearings and how to find the correct ones (don't want to pay the dealer).
> Any insight will be appreciated.  Thx.
> Radek
> 88 90Q
> 91 V8Q
> 5-sp.
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