just a few questions, do the solenoids just go bad, or does something else have to happen? mine just started out of no where,, on a drive home. dose not change out past second. very slow take off with high rmps. next day had the code scanned and Shift Solenoid B came up. I currently have it at home,, pan off, new solenoid in. but after reading many posts it sounds like it could be many things. The pan gasket, now that i have it off, do i really need a new one? the old one looks fine, and in good shape. Last, how much fluid does it require to fill it back up?

 

I had a 99 Silverado that one minute it was fine and the next I had the same solenoid go back. It is fairly common I think in these transmissions and they are pretty cheap.

As far as the gasket goes I would go ahead and replace it, I don't think they are expensive either and might as well do it. I'm not sure about how much fluid they require.