It won't grind when you try to put it in gear unless your synchros are bad or you are trying to put it in an unsychronized gear (like reverse on most cars--the Contour has a synchronized reverse).
The function of the synchros is to prevent the gear from engaging until the speeds of the input/output are the same.
When you find that takes a lot of effort to put the transmission in gear, the synchros are what is keeping it from going into gear easily. Try pushing harder enough times and you'll ruin them, then it will start grinding.
