I fixed a transmission leak a week ago on my 2000 and now it is shifting kind of hard (not real hard but enough to notice the difference from before). Could this be because I added about 2 quarts of Dexron/Mercon generic "coastal" autozone fluid (had it on hand) to replace lost fluid instead of going and getting some Mercon V?

I cannot imagine that 2 quarts of mercon would cause that...but I could be wrong.
FORD came out with Mercon V to correct transmission "shudder" that came up on some transmissions with Mercon.
Take note that the fluid should be changed at least every 30K miles.

I'd bet it has more to do with the fluid level. There is a TSB on your year Windstar that calls for the fluid to be near the top of the hash on the dipstick to avoid harsh shifts.

Yeah, I thought it was unlikely but really needed a second opinion. Thanks. The leak was coming from the low/intermediate servo cover. I had to pull the cover and the gadgetry behind it to repair a stripped thread. Seemed to go smoothly though. But now this hard shifting.

Any other ideas on a cause?

Thanks alot!

I'd bet it has more to do with the fluid level. There is a TSB on your year Windstar that calls for the fluid to be near the top of the hash on the dipstick to avoid harsh shifts.

Will check that immediately. Thanks!