I gotta 1999 silverado 1500 z71 4wd... I put the truck into 4-hi for the first time in about 5-6 months and as soon as you start to drive forward there is a loud Grinding/Growling noise coming from the driverside/diff-side. I drained the gear oil and there were not any metal shavings or chunks. It makes a noise that sounds like metal to metal brake pads.... If neone can help out i would be thankful!

 

did anyone ever help you out with this? I have the same damn problem on my 07 classic...