Hi everyone- I'm new to the forum and hoping someone may be able to shed some light on my issue. I bought a 2014 TRD Off Road with 47k miles about a month ago and I really love it. Drives great, looks great, feels great... but there is one issue I can't get past. Every time I am on a rough road (i.e. cobblestone city street, gravel road, etc) or even just driving over a manhole cover in the road, my truck will make this high pitched chirping sound (actually sounds very similar to a small bird's chirp) as the truck vibrates/absorbs the bump. It sounds like it is coming from inside the cab, but it's hard to tell. Seems to be a bit more isolated in the back right (passenger) side of the cab, or maybe where the bed meets the cab. I have read online that a common cause of squeaks are bad bushing and/or leaf springs. While I haven't ruled these out, I don't think this is the issue. I have tried everything from jumping up and down on the tailgate, standing on my running board and shaking the cab, even sitting in the back seat and having someone else do these motions, and I cannot replicate the squeak/chirp. Nothing I do as far as physically pushing or pulling on the truck will cause it to make any sort of noise, but the second I hit any kind of dip or bump in the road, it sounds like a flock of sparrows singing in my back seat. This is my first truck and when I first noticed the sound, I just chalked it up to being a "truck thing." But then I drove my buddy's 2014 TRD Sport and his was completely silent on all surfaces. Could my bed be loose? Or maybe it could be as simple as a bad bushing? Please let me know if you have had a similar issue and can provide some answers. Thanks!