4 Speed 2nd Gear Question ?

Good morning guys. I've noticed that second gear doesn't seem to be fully engaging. I mean that when you shift it doesn't feel like it is going in the whole way. So I unhooked the shifter and adjusted it, still the same. I unhooked the shifter again and shifted the transmission by hand and it is not going in second all the way. All the other gears are going in the whole way. Then last time I drove it I was coasting down a steep hill in second and it popped out. I can shift to second at high rpm ,quite fast, and doesn't seem to be any problem other than sometimes there is a slight grind. I was atributing that to me, but maybe this is a trans issue as well. I will take the trans apart, but I really don't have the time right now so I was wondering if someone could shed a little light on this for me. Has any body had this problem and what will I be looking for when I take it apart ? Thanks fellas.