It is supposed to add water at the beginning of the final spin to get some suds out. If it is adding at the end, then changing the timer should have fixed it, so t his is a mystery. I would suggest checking the wiring to the valves, and changing out the valves, but honestly, I don't know why that would work. It's just the only suggestion I have.

The problem of adding water at the wrong times is likely a bad load sense switch. This is a high failure item on this washer, but that should have nothing to do with your other problem. If you put the timer at drain/spin and it agitates instead, that would be a timer problem.

Eric

I have a Whirlpool Washer model GSX9750PW0 which adds water during the spin cycle so at the end the tub is still full. Can't seem to find the position on the timer to drain the tub. Problem until now has been intermittent, i.e. sometimes it works as it should and then other times it adds water during spin cycle. Clicked on your reference to load sense switch but it takes me to temperature switch. when I search for load sense switch, I do not find the part.