Help! I just changed my gear oil and pulled the transmission shifter to pour the new oil in thru the top. Now it is stuck in 1st gear. It shifted fine before and the pin and the plastic piece are in good shape. What could I have possibly done???     

did you pull stick when was in neutral? Is the "guide bolt" busted now?- mine jammed in third when it busted. Be careful that broken piece doesn't fall into trans. Use magnet to hold it.

Problem solved. I pulled the stick when it was in first. Used a screwdriver to shift to neutral and all is good now.