Dodge: '90 Caravan transmission

I have a '90 Grand Caravan with a 3.3 and automatic overdrive (604 I
presume).
I bought it for parts because the owner said the trans was slipping,
but that I could still drive it (wrong--it wouldn't move).
To make a long story short, I never checked the trans fluid because I
naturally figured he'd done that when it started acting up. But he
didn't.
I pulled it home on a car dolly and checked to find no fluid on the
dipstick. I filled it and it shifted fine, however in OD it jerked
some, which I knew right away was plugwires, replaced them, runs great.
BUT, I notice when you initially shift into drive there is a
noticeable hesitation and the engagement is somewhat "soft."
I would like to know what that means, as far as what specifically is
occuring inside the trans to cause this, does it mean the trans is
likely to fail soon, etc. Any 604 techs out there?
Otherwise it shifts perfectly, including tc lockup, even though the
guy apparently drove it around really low on atf, a lot.
It had a leaking axle seal and I drove it like that for awhile, adding
atf as needed, hence the fluid is reasonably clean but I haven't changed
the filter--which I don't want to do if that isn't the cause/cure of
problem and the trans is on its way out anyway.

Detailing Dude wrote:
I think the hesitation is a dodge thing. I have a 2001 GC and my wife
complains everytime I drive her............................and she hates
that. I has always done it.

Cecil