Ok, so I took the truck to another shop that normally does my alignment and such... luckily, one of the guys was familiar with 4x4s so we took a quick spin to see if he could help pinpoint what the problem is...

According to him, my pinion gear is going out at the very least. He said no fluid change is going to help that. It feels like it's slipping because pinion gear is going bad and the whine is coming from (clutch disks) locked in and not releasing. He told me to get this thing into a shop that works on these or the dealer pronto.

Later, when we pulled back up to the shop and I brought up the fact that the truck was recently dragged on a flatbed both him and their service manager's eyes widened and they promptly confirmed that there is a 99% probability that this is the cause of my issue. They said that dragging the vehicle on the bed is one of the worst things you could do to your driveline and what's worse... they knew that this particular wrecker simply dry-drags the vehicles onto the flatbed.

I remember having that suspicion after the tow truck driver gave me that story because I didn't smell any wd40 anywhere on or around the truck when he brought it back... and purposely took some pictures at the time just in case. Guess what, a reviewed the pics, again, and I don't see any wd40 or oily residue on my tires, on the inside of my rims, on the rims, on the cladding, or inner wheel wells.

Oh yeah... and I almost forgot - I'm not covered by a powertrain warranty as I am a second owner of the vehicle so if the tow service gets out of this, looks like I'll be getting very familiar with the insides of my front axle.