95 c1500 short bed single cab 305. 130,000 miles There is a loud squeak that is not constant but squeak.squeak.squeak about 3 times per turn of rear wheels cannot figure out where it’s coming from or what it is. It started out only doing it in reverse but wouldnt do it while rolling backward in neutral or forward. Now it is slowly starting to do it while going forward. I have checked all breaks and deferential fluid and greased the drive shaft U-joints. My exhaust is loud so I can’t figure out the exact location of the noise. Any ideas? Could it have anything to do with the transmission? Is it possible to grease the axel? Iv ran out of ideas Now that i greased U-joints i had to take the rear end of the drive shaft to get to the grease nipples and ever since then the truck now jumps and makes a clunk right before i accelerate. Thanks for any help!