When you use any slides including drop down beds you are suppose to hold the button down until you hear the motor quit. Sometimes 30 seconds after you think that it is in or out. Do this going in and out. It keeps the motors in sink. That's probably why its not coming in equally and leaving the gap on one side. It wont hurt the motors they kick out on their own. Hold it in till you do not hear anything and this should resolve your problem. This is probably why you hear the struggling to get it in and out. Its bindlig