4runner316

Today I was driving on the freeway and all of a sudden I heard and felt something hit the undercarriage of my vehiche, right underneath my driver seat. Either I just hit a rock in the road and my tire flicked it straight up - or something fell off and somehow it smacked up against the undercarriage. Well anyways, once I got off the freeway and went to put shift into park I noticed something wasnt right. Instead of my shifter smoothing sliding from drive up to park, it got stuck at reverse and didnt want to move up up at all. I slid it back down to drive and then up to park - but there was alot more friction then ever before. I only got to test it out a few more times before I got home - but its pretty much doing it all the time now. The shifter has a lot of friction inbetween the gears. It also seems like it is making a much louder audioable "clicking" sound from outside the vehicle when I am shifting inbetween gears while parked. Any thoughts on what this might be? Was the noise I heard and felt just a coincedence?