Rear differential lock always on

[Huw Powell]

ABS, haha, long dead.  Relay pulled, switch gone. The rear is not 
locked, everything is different when I do that.

Robert Rossato wrote:
> Hmmm, I wouldn't expect it to be a Torsen thing.  My S6 is essentially the
> same setup as the 90Q - Torsen center diff and lockable rear diff.  The only
> time I have had shuddering from the rear wheels was when I locked the rear
> diff on dry pavement on purpose - just to make sure it was engaging.
> Otherwise she's quiet.  Full lock or not.  
> 
> Sounds like the rear diff is stuck in the locked position.  Is the "ABS Off"
> light on by chance?  That comes on when you engage the rear diff lock, which
> should disengage on its own at 15 mph.  If the light is on and it's not
> disengaging at 15 mph then it sounds like there might be something foofed
> with the vacuum switch.  If the light is not on, then it's possible that the
> rear diff lock is internally stuck.  Try crawling under there and see if you
> can engage/disengage manually.
> 
> Bob
> 
> -----Original Message-----
> From: quattro-bounces at audifans.com [mailto:quattro-bounces at audifans.com] On
> Behalf Of Cody Forbes
> Sent: Sunday, April 25, 2010 7:57 PM
> To: audi at humanspeakers.com
> Cc: Radek; quattro at audifans.com
> Subject: Re: Rear differential lock always on
> 
> That's a torsen thing. The torsen is locking up because of the wheel  
> speed differentials caused by the sharp steering angle. People tend to  
> call it "torsen shudder". My A8q does it too (as should all torsen  
> equipped cars).
> 
> -Cody (mobile)
> 
> On Apr 25, 2010, at 7:27 PM, Huw Powell <audi at humanspeakers.com> wrote:
> 
>> My '89 90Q does that, with the lock not engaged.  It probably  
>> shouldn't
>> but it does.  Every day when I do a full lock (steering) 180 degree  
>> turn
>> to leave my parking lot.  I ignore it.  My Chebby truck does it  
>> too.  I
>> ignore that as well. I ignore a lot of things that would otherwise
>> bother me.
>>
>> (resisted urge to sign with four tildes...)
>>
>> Radek wrote:
>>> H'Audi;
>>> Car is a 1988 90Q.  A question I couldn't find the answer to in the  
>>> Bentley:  is the rear differential lock actuator on when pulled or  
>>> when pushed by the vacum thingy?  The car has a shudder coming from  
>>> the rear end when turning at slow speed.  At highway speeds, no  
>>> issue.
>>> TIA
>>> Radek
> 
> 

-- 
Huw Powell

http://www.humanspeakers.com/audi

http://www.humanthoughts.org/