I disconnected my automatic garage door opener and I can see when closing the door manually, and it's almost at the bottom, the remaining panel gets stuck and it won't fully close. There is no visible barrier in the tracks or anywhere. However, I can't fully see the springs in this position. I'm not sure if the springs are the problem because I can open and close it fine up to that position. It's been working fine until today when I found one of the bottom wheels was displaced. I put it back in and it's still not fully closing.
Any idea what might be wrong?
Update: 
Best Answer
Clearly something is binding, catching or blocking the door sections or roller wheels in the tracks. It could be as simple as one of the track mounting bolts has come loose and is binding with the roller as it tries to go by.
It is also possible that the door is becoming wedged as it gets toward the lowest position. There may be a small diameter cable attached to the lower section of the door on each side that goes up toward the top and spools onto the spring assist lifter at the top. It is possible that one of these cables has broken, become detached or has doubled over itself in the spool mechanism. One or the other of these could cause the door to not be supported uniformly on each side or the cable not allowed to un-spool nicely on one side.