Re: changed the differential oil, still no improvement

["Fred Munro" <munrof@isys.ca>]

Raffi;

    If the noise is coming from the middle of the car, check your driveshaft
central bearing and U-joint. The U-joint should be lubed regularly.
    Differential whine is usually load sensitive - in some cases it whines
under load (acceleration or deceleration) and in other cases it whines under
float (just enough throttle to keep the car moving).

HTH

Fred Munro
'91 200q  261k km
-----Original Message-----
From: Raffi Tomassian <tomassian@glaserworks.com>
To: quattro@coimbra.ans.net <quattro@coimbra.ans.net>
Date: Sunday, November 01, 1998 9:15 PM
Subject: changed the differential oil, still no improvement


>Hi All,
>
>A week ago I asked for help regarding the whining noise coming from the
>rear of my car ('87 4kcsq) at around 30mph, gradually thinning (the whine
>that is) untill I reach, say 80mph, when I don't hear it any more.  The
>replies I got directed me to the rear differential, so I armed myself with
>some Valvoline 80W140 GL-5 (They never carry and only order RedLine in
>cases of 12 where I live), drained the old, probably '87 diff. oil and put
>in the Valvoline stuff.  The situation now is unchanged; the whine is
>seemingly there to stay.  Any suggestions where I should check next?  At
>the advice of a friend I clutched several times while doing 65-70 on the
>interstate to check if the noise would go away or change; supposedly if the
>problem is in the differential the whine should change if it is disconected
>from the engine (therefore clutching) with no audible result.  Any thoughts
>on that?  Suspecting the wheel bearings somehow does not make sense to me,
>since to me the noise comes from the middle of the car.
>
>Thanks, as ever, to all respondents,
>Raffi
>
>