Is my tranny ok?

[Jim Camery <jcamery@domain.elided>]

When my '73 1010 Travelall with a 727 sits for a week or so, the tranny
gets lazy.  When I first start it up and put it in gear (either drive or
reverse), there's no action for about 15 seconds.  Eventually, with some
revs, I get some action.  A block down the road everything is normal.
Its been like this ever since I bought it about 15k miles ago, and I've
used it to pull very heavy (4+ tons!) trailers.  It has a tranny cooler,
and I'm good at keeping the fluid up.  I had the filter service about
10k miles ago.  Once its warmed up, response is immediate, just like in
a new car.

Is this normal behavior?  Is it just the fluid pooling?

Jim Camery
'73 Travelall
'68 Travelall
'73 VW Convert
'96 SAAB 900
'59 MB Unimog
'56 Cris Craft 26' Cruiser
'64 Cris Craft 37' Cruiser