Speedo & difflock conversion for later trans install

Ben Swann benswann at comcast.net
Mon Jan 22 01:26:03 EST 2007

Thanks - this sounds like the way to go for me.  Since I have everything out,
it have a good opportunity to make something up.  I'd appreciate any more
details/pictures of how the car was converted.


-----Original Message-----
From: Mark J. Besso [mailto:mbspeed at maxboostracing.com] 
Sent: Monday, January 22, 2007 12:38 AM
To: 'John Cody Forbes'; 'Ben Swann'; quattro at audifans.com
Cc: speedmark at maxboostracing.com; 'Bob D'Amato'
Subject: RE: Speedo & difflock conversion for later trans install

The lock actuators were from a GMC S15/Jimmy power door lock setup.

Bob fabricated adaptors to utilize the brackets for the original vacuum
actuators.  He ran the wires through the hollow steering column to a small
(carbon fiber) box mounted to the steering wheel.  There were three switches
on the box.  The left switch triggered the center diff-lock and the right
triggered the rear diff-lock.  The switch between them swapped the direction
of the actuator.  If it was to the left, it would engage whichever diff-lock
you triggered.  If it was to the right, it would disengage whichever
diff-lock you selected.

Since the stock sensors were never removed I still had the lights in the
console to tell me when the selected diff-lock was engaged or disengaged.

It was 100% reliable and the action was immediate.  I miss having that setup
and I really, REALLY miss having that car!


-----Original Message-----
From: John Cody Forbes
Subject: Re: Speedo & difflock conversion for later trans install

Ben Swann wrote:
> Also, need info. On converting to accommodate the vacuum difflocks,
> as the '83 trans. Diff is activated from cable in rear  - I think.
> It would be nice to eliminate the cable which  snagged when dropping
> the engine and trans out - the last thing I overlooked when yanking
> motor and trans.

I've got nothing usefull for you on the speedo, but I think the way to go
with the diff locks is electric using door lock actuators from a junk yard.
I'm going to do that to my car first chance I get (which may be a while
since I'm broke hehe). No more stupid vacuum lines to deteriorate, no more
brittle plastic connections on the actuators, no more waiting for them to

I've cc'ed Mark Besso and Bob D'Amato - they did this to Marks rally car.


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