Screw in my RC car will not stay in?

(this isn't really an RC problem so anyone could be ale to help me so read on!!) iv had this problem since i got the car. The screw going from the steering to the servo will not stay in its upside down and the servo obviously turns a lot so that's probably why its coming out but what could i do to stop it? iv tryed super glue and that failed and iv tryed masking tape but all that does is catch the screw when it falls out. please help me:(