You need to narrow down the problem before you buy parts. This will nickel and dime you to death. Please don't just start changing parts. Check the SC oil level, and get a mechanic'* stethescope. Find the real problem.
If you do that, be careful near the moving parts. A mechanic'* stethescope is mechanically isolated and made from soft aluminum. If it does get caught in something, it won't hurt you. A screwdriver handle in your ear hurts. Mos95b told me so.
So i checked my tension assembly today, the thing is catching once it gets enough tourque on it. I think that'* where my noise is comming from. I think i have to go to the dealership to get one. Any ideas how much?