I’ve had my truck for about a year and a half now – currently with 165k miles on the clock. While driving highway speeds (60-70mph for example), I’ve noticed a sort of rattling/ticking noise that occurs when I happen to be ‘feathering’ the throttle. It does not appear to be present when driving around town, or at idle. During full deceleration, or hard acceleration, it does not seem to make the noise either. I’ve been unable to establish if it is temperature dependent. Also difficult to tell if it is actually coming from the engine, as the only time I can hear it is when I’m on the highway. From my readings through searching the site, I’ve written off the transfer case chain for the time being, as the sound does not appear to be 'substantial' enough. With low to moderate volume on the radio, I can pretty much drown the noise out. I would like to do some more investigation to see if possibly the flex plate is beginning to fail. Following that – possibly an exhaust issue? I am leaning more towards a possible driveline noise as it seems to manifest itself when the revs are above 2500 and when the throttle is being ‘feathered’ and thus a sort of ‘shifting’ load on the engine and/or driveline. Currently the engine is running/idling fine with no odd warning lights or trouble codes. I am considering removing the access cover on the bottom of the trans to try and peek around the flexplate area. Or, if this is in fact normal operation – the peace of mind that nothing is going to self-destruct in the immediate future! Any thoughts or suggestions are appreciated!