So this past weekend I replaced all the idler pulleys and both tensioners on the X. It was a total of 7 idler pulleys and 2 tensioners. Not all of them were bad but all the accessory pulleys and two of the S/C idlers were toast. I think it was a combination of the truck being up on jack stands for 3.5 months this summer and the fact that the engine idlers have 136,000kms on them and the S/C idlers have probably about 100,000kms on them.(S/C was used when I bought it). I got the Gates engine idler assembly and I had to buy the S/C ones from Magnuson (through Superchargers Online). It was rather pricey to replace all of them but I didn't really have the option of taking them off and pressing the old bearings out to get new ones pressed in (kinda hard to ride a motorcycle to work in the winter in Canada). I'm going to keep the old ones and do exactly that, press out the bearings and put new ones in. For those that want to change the engine accessory tensioner, it will probably take you about 5 hrs to do it. You have to take the alternator and A/C pump off to get to it. I'm glad that I changed them when I did though, the bottom ribbed S/C pulley was really messed up and was close to either seizing up or blowing apart. Has anybody else replaced the S/C idler pulleys?