[Vwdiesel] TDI alternator pulley

[brian gochnauer]

It's is a 'sprag clutch' (couldn't find a good example pic) and the reverse
direction resistence isn't really of much value as long as it locks in the
'forward' direction.
It's there to reduce the spinning forces internal to the alternator when the
engine is shut off.
The tensioner died of it's own accord.
imho

BrianG
Iowa


Date: Wed, 15 Sep 2010 22:27:17 -0500
From: Shalyn Shourds <sshourds at flash.net>
Subject: [Vwdiesel] TDI alternator pulley
To: vwdiesel at vwfans.com
Message-ID: <4C918E95.4030503 at flash.net>
Content-Type: text/plain; charset=ISO-8859-1; format=flowed

 A while back, I saw that my '00 Jetta TDI accessory belt pulley was
bouncing all over the place.  I searched the TDIclub site and there
seems to be a history of alternator pulleys failing causing the tension
on the belt to exceed the dampening ability of the tensioner.  Tonight,
I pulled off the belt and looked over the system.  The typical alt.
pulley failure mode appears to be that the one-way clutch doesn't lock
in either direction.  I did establish that the pulley locks in one
direction.  I also noticed that in the other direction, it has far more
resistance than I would expect from a bearing, but I don't know what's
typical of this kind of clutch.  Should it be completely free-wheeling,
zero resistance?  I also ascertained that the little hydraulic strut on
the tensioner is completely blown--oil leaked out everywhere.  I
definitely need to replace it, but did it die, or...was it murdered by
the alt. pulley?

Thanks,

-Shalyn