95 continental transmission hard shift problem

I have a 1995 Lincoln Continental with 102K miles. It started to shift hard from 1st to 2nd. The other gears shift fine. Does anyone know what may be the problem? I checked the trans fluid level and it is okay.

Thanks!

I would guess a sticking valve or a torque converter on it's way out.

I would start with a bottle (or 2) of LubeGard Red (http://lubegard.com/automotive/trans_atf.html). I can't speak first hand re: other additives.