After putting it off for quite some time, I figured 120K on the OEM belt was enough. I wanted to have the place where I go for most matinence (Other than DIY) do it, but they charged $95 and I got the belt on Rock Auto for $25. Easiest thing I've ever done to my truck. Took only about 25 minutes to take off the old and put on the new (Dayco). Never thought it would be that simple!