On Saturday I tried to replace the serpentine belt on our 2007 CX-9 Sport but wasn't able to get the new one on. I was able to figure out that you have to take the right front tire off and remove a panel from the wheel well to gain access. I used a 13mm open ended wrench to move the idler pulley and the old one came right off. I tried for about two hours to get the new one on and there was no way it would go. What a horrible design. First, the bolt that holds the idler pulley to the torsion arm faces the engine block and there is not enough room to get a socket wrench in there. Second, the direction that you need to turn to relieve tension is also the direction to loosen the bolt that holds the idler pulley on( yes, mine did loosen but I was able to tighten it up enough to allow it to relieve tension without it coming loose again). Again, what a horrible design. I have never had a problem like this.
I put the old one back on in about two minutes so I am guessing it has stretched enough to make it easy. The new one I'm putting on is a Dayco that I bought at Advance Auto and is about an 1/8" wider than the Motorcarft part that is on there now.
Anyone have any advice on how to get the new one on? Thanks.