I noticed a post about belt whine. I too have a really bad whine that seems to be getting worse. I cannot pin point where it is coming from. I have 160,000 miles on my F150 4.9l '94 and have never replaced the tensioner. What does replacing it entail? Is this a reverse thread nut? It looks to me like a simple matter of getting a socket/breaker bar on there and taking it off but I know there has to be more to this job that this. Any help, clues or ideas I would be appreciative!