I would try some Seafoam AT treatment first.  Worked well on a balky
Ch*rokee AT I had a few years ago.  Afterwards, put in clean fluid, run it a
little and drain and replace again to get most of the old stuff out of the
torque converter.
 You might also remove the governor and check that its passages are open.  I
have seen a small amount of lint in there prevent shifting.
   The other, more challenging, approach is to pull out the valve body and
take it apart, making sure all the valves slide well.  You need to be very
careful, organized, and clean.

good luck,
Larry A.

On Wed, Oct 1, 2008 at 9:41 PM, Jeff Palmer <jpalmer@mts.net> wrote:

> Hey all,
>
> If someone can give me advice I'd very much appreciate it.
>
> I have an 85 Westfalia GL with an automatic transmission.  290k
> kilometres.  Recently the transmission began hesitating when shifting
> from second to third.  It is more pronounced when it is cooler
> outside (like now).  After it shifts for the first time into third,
> it never hesitates again.  The fluid level is fine although I don't
> know what kind of transmission fluid my mechanic uses.
>
> Any suggestions?
>
> Thanks again
> Jeff in Winnipeg
>