LOUD whinning noise when I drive! HELP
Hey, new to post but have been coming here for advise for years. Here's whats happening. As i accel a whining noise starts and gets louder as i go faster, and softens as i slow down. kinda like being wound up, and then down with my speed. it sounds like its coming from the rear of the truck. it started a couple months ago, very faint, but has gotten louder. it doesnt change pitch if i down shift on the highway or with the OD off. it doesnt change if i throw it in neutral either. At first i thought it was tires, jacked the rear end up and put it in drive, still had loud whining. and i couldn't really tell where it was coming from. i'm thinking its the trans or diff. i do have a limited slip. i checked ATF and its good, i popped the rubber plug on the diff off and checked fluid level which was fine. I had both flushed a couple years ago.
any insight advice or solutions are greatly appreciated!