My 08 T now has 145K on it and it sounds like marbles bouncing around near timing chain area. From what I have read on hear is that the timing chain guides/tensioner can cause this. Any one know how long it takes to replace said parts, just trying to figure out if my truck is going to be down for a day or two or week?? I will be doing the repairs, not paying $$$$ for something I can do. Just trying to find out how many days to take off work.