The sender is removeable with the tank in place. BUT try this.
Fill the tank to the rim.  Drive over rough traine. This fixed mine.

            Eric                   86-VW4x4
            vw4x4@fyi.net          72-240z
            Pittsburgh, PA USA     1936-Chrysler

On Fri, 7 Aug 1998, Kim Brennan wrote:

> The gas guage on my 86 GL Syncro, is now reading full all the time that power
> is on, so it appears that the sending unit (in the gas tank) is in need of
> replacement.
>
> Is this a task that can be done without pulling the tank? Remember, the tank
> in the syncro is in the rear, above the transmission.
>