Just went through this, so quoting Bentley:
ATF level, checking:
    ATF at operating temperature of approx. 60�C (attained after driving approx. 6
miles
    after a cold start).
    Vehicle on level surface.
    parking brake engaged.
    selector lever at P.
    engine idling
    use a lint-free cloth to wipe dipstick
 Well, there are two different dipsticks and I don't know when they changed, but in
either case, it says fill to between the marks and DO NOT OVERFILL.
Quoting some more:
    Use only ATF marked DEXRON. Do not use any additives.
    "The ATF used in production vehicles has changed in composition and color from
that used in previous years (1980-1984).
    "Previous color: red
    "New color: red/brown
    "The new ATF discolors to black/brown after only short running times. This has no
effect on quality of fluid, etc. etc.
    "The new ATF and types of ATF DEXRON used previously can be mixed.

Jerry

----- Original Message -----
From: <JordanVw@AOL.COM>
To: <vanagon@GERRY.VANAGON.COM>
Sent: Sunday, November 19, 2006 6:58 PM
Subject: Re: automatic transmission oil level?

> In a message dated 11/19/06 8:38:07 PM Eastern Standard Time,
> garyowen@MAGMA.CA writes:
>
>
> > Have 85 Westfalia 1.9 L with automatic, how should transmission
> > fluid level be checked?
> > Warm up/ cold?
> > engine running?
> > In P or N ?
> >
> > How critical is maintaining proper level?
> >
> >
>
> auto transmission fluid should be checked when engine is up to full operating
> temperature, with shifter lever in "Park" positon, and vehicle in level
> ground.   ATF should be red, not brown, and full to the top mark.   low ATF fluid
> levels can mean there is a leak somewhere, and can cause damage if level falls
> too low.  also levels that are too high can mean there is a problem such as
> final drive fluid leaking into the ATF and that can also cause problems.
>
> chris
>