95 Camry 4cyl goes forward in drive, neutral and rev won't work all of a sudden. Any ideas

Mechanic may have twisted a coolant line leading in or out of radiator like a twizler thus not allowing enough pressure to build within transmission, all while not leaking a drop. I forgot to mention there are transmission fluid lines going to and from radiator to cool the fluid.

I had my radiator recently changed out by local mechanic. Do you think that's what happened and if so what do I look for our how I fix.

Check fluid level. Transmissions are not my strong point. Look for kinked or twisted transmission cooler lines. If they look good, and you feel up to it and you have ramps or jack stands. Put a new filter and gasket on the transmission. If that doesn't work you might want to take it in.