Throw Away

Well slap me right on the ass, and call me Shirley. thats what i've got based on what i can tell. I really appreciate the help diagnosing. Any recommended next steps? From a quick google i read it'd be fine to continue driving on but I'd be interested to get some second opinions. Should i get it worked on as soon as I can? should i ride it out till something breaks even further? Or do i look into just trying to quiet the noise best I can? Honestly not sure, so any advice would help. Once again, really appreciate the help.

Howdy, I don’t anything about trucks or vehicles in general so my problem has left me especially stumped. I’ve got an 08 Sierra SL. Got it at around 52k miles, have since put on about 10k in the few months I’ve had just driving to and from work. I’ve noticed that a squeaking sound has developed with the truck mechanically. Happens strictly at low RPMs and while sitting still in drive or park. I’ve taken the belts off, ran it, still squeaks. I’ve replaced belts, still squeaks. I’ve had one person say could be the transmission, so I filled that sombitch full of Lucas fix and a new bottle of fluid. Seemed to quiet the squeak but it was still there, now it’s back to its old loud glory. I’ve had another say could be something in the motor. It’s stumped a handful of people when asked “hey, you have any idea what that squeak could be?” Admittedly I’ve yet to take it to a mechanic shop, so feel free to tell me to kick rocks, but I wanted to know what y’all thought before I took him anywhere. If anyone has any idea whatsoever feel free to let me know. Forgot to mention, truck still runs great even with the squeak and all, so I could be in a position to “run till something breaks.” Ah well, thanks boys