94 caravan transmission adjust

I have a 94 caravan with 3 speed auto. Doesn't shift into 3rd until 50 mph. How can I adjust this? Does this trans have bands?

There really isnt much you can do about the late shift, I had a 95 that was doing the same thing, I drove it like that for almost 2 years before the transmission went out on it. On yours, is it worse when the engine is cold, then gets a little better as it warms up?