Yesterday one of my client asked me "I am planing to change the server of my website for some technical reason and want to know if the transfer hurt my site rank? ". My client was informed by the server support team that if he transfer his website from their server to another one he will loose his site rank. He was so scared to do that. 

The answer to his question is a big NO. The server change will not hurt the website ranking as long as the new server is not a penalized one by google. At the first few days their might be a DNS reset issue for the newly transfered website. It is normal but it will be resolved with in few days and the website will regain its previous site rank.