I fixed that problem by installing a cluster on my 84 Westy and 84 GL with
ones from an 85.  Now it's spot on.

You could retro-fit just the 85 Speedo into your 81 but you have to use the
upper clip-on cable from an 82-on or bypass the "time box" with a cable
from a Diesel Vanagon:

http://www.airheadparts.com/vintage-vw-parts/speedometer-cable/cable-speedometer-2240mm-push-on-type-251-957-803-e

Note: Ran outa stock today, more on the shelf Wednesday :)

--
Jim Thompson
84 GL 1.9 "Gloria"
84 Westfalia 2.1 "Ole Putt"
72 411 Station Wagon "Pug"
75 914 1.8 "Nancy"
Full Timing From March 1999 To January 2012
oldvolkshome@gmail.com
http://www.oldvolkshome.com
Find me on Facebook:
http://www.facebook.com/people/Jim-Thompson/100000710343835
***********************************

On Mon, May 6, 2013 at 1:28 PM, Karl Ploessl <karl.ploessl@gmail.com> wrote:

> so I finally got a GPS in my van. And what do I notice?
> Speedometer says 60 mph and GPS says 45 mph! At 70 (speedometer) the GPS
> says 62!
> I am running Michelin Agilis 61 in size 185/14 C and it is a Westy 81
> aircooled. And it is in Delaware to satisfy Scott.
> The question I have: does this discrepancy also affect the odometer?
>
> ------
> Karl
> 1981 Westy "Jenny"
> 2000 VW Jetta GLS VR6
> Wilmington, DE
>