My new van has a problem shifting. Under normal throttle, it shifts very hard at about 25mph and then into third at about 40. If I let off, it'll shift slightly easier but still hard, and kicks back out of third under 35 with any throttle. If I floor it, the shifts are at the same points but a bit softer presumably because of the kickdown's interaction. The van previously took teeth off the pinion gear according to the last owner, which I suspect was caused by this shifting issue, and I'd rather not have that problem.
Does this sound like a bad vacuum control? How should that be tested or adjusted?

 

could be a bad vacuum issue, but when my vacuum pump went out, it wouldn't shift at all. Maybe at low vacuum, it'll shift hard, but I doubt it.

To check your vacuum, does your brake assist and climate control work ok? if yes, then you probably have an OK vacuum pump.

 

does it shift hard when you manually shift? if yes, then your vacuum probably has little to do with the hard shifting.

 

Try adjusting the VRV on the side of the injection pump, tip the top towards the front, also it could have the wrong modulator in it, I forget what color it should have, black or purple.