Date:         Mon, 11 Sep 1995 23:42:19 -0500 (CDT)
Sender:       Vanagon Mailing List <vanagon@vanagon.com>
From:         Joachim Beek <beekj@smd6.jsc.nasa.gov>
Subject:      Re: Need a speedometer

On Mon, 11 Sep 1995, Harvey Chao wrote:
> 
> A common failure mode for VDO speedo/odometer/tripmeters is the gear that
> drives the tripmeter off of the odometer.  This is a small plastic (nylon?)
> gear on the extreme right end (as you look at the face of the speedo)of either
> the trip or odometer shaft that transfers motion from the upper (odo) to the
> lower (Trip) shaft.  
> 
> To access this, you have to pull the speedo.  I had this same problem with my
> '81 Rabbit.  What happens is that this little gear cracks radially, and then
> doesn't grip the shaft tightly enough to turn with the shaft and transmit
> torque to the other shaft.  
> 

This is what happened to my 78 Scirocco.

> 3)  In unlucky cases, the crack will either go all the way across the gear, or
> there will be more than one crack and the gear will then be in more than one
> piece.
> 4)  Some people have tried to glue the gear back together, but I think the
> problem is that most glues won't properly "grip"/adhere to the plastic.

In my case, I was lucky.  A single solitary lonely crack; however it
was amenable to being fixed by carefully dabbing a bit of superglue on
it.  Three Texas summers and 30k miles (it's up to 170k now) later, and
no problem.  However, the odo on my 90 Vanagon abruptly stopped turning 
just a few days ago (not at all gradually as on the Scirocco).  Took
the instrument cluster apart tonight (thank the VW gods that this is
easier than on a 78 Scirocco!) and found that the odo spindle, not the
tripmeter, had come out of its mounting hole.  (Must have hit a good
pothole to knock that loose!  At least I hope that's all there was to
it.)  Pushed everything back together the way it should be and tomorrow
will tell if I have to do further surgery.

> However - It occurs to me that although the speedo faceplate may vary between
> Vanagons and rabbits, it is a fair bet that a VDO speedo of the same year
> vintage regardless of vehicle (as long as the top end speed markings are the
> same) is a VDO speedo, and you may be able to cannabalize parts.  Just be
> aware that this was not an uncommon problem, and a used speedo may have the
> same problem.

True, true , and true.

Finally, it's good to be back on the list and be deluged with mail.
Went on vacation for 5 days (:^) and promptly got kicked off by the
listserver :^(.

Funny, the Golden Retriever list didn't do that to me...are you guys
trying to tell me something?

Joachim
--
I'm not an engineer, but I play one at work.