A general automatic transmission question

[fastivaca]

Hello all,

What would cause the automatic transmission in a '97 Astro to shift very hard after a long run on the highway? It shifts normally after sitting overnight so I'm guessing some kind pressure regulator.

Would chaning the transimission fluid and filter help?

Thanks for the input.

[monkeyracing]

I'd check the fluid, and the filter. It's not likely to be low fluid, seeing as that would cause soft to non-existent shifting. After a long highway run I suppose it's possible that a certain amount of pressure could be built up within the trans, and a clogged filter might help hold some back.

How much mileage have you got on that van? I know those 700R4s are a little sensitive when they're worn.

Jim