Yeah that is what I thought. It turned out that after my cdl install i would hear a sound only on acceleration when warm. If it was in neutral I would not hear it if I rev'd the motor. if the t-case was in neutral and transmission was in Drive I would not hear it. WHAT could it bE!??

I checked to make sure everything i removed during the CDL install wasn't loose. I checked the drive shafts, checked exhaust, i jacked up each wheel individually and put it in Drive to see if I would hear anything. I checked the cross beams, checked the heat shields etc..

Stil couldnt figure it out. Tranny was serviced back in March (by me) twice because i feared i might have done it wrong the first time...

Transmission shifts smooth up and down. I was going crazy. Yesterday i got under her and just started looking around for a whole hour. i was looking straight up at the motor with my feet towards the rear of the car and then I thought...perhaps my exhaust has some broken/loose shards of something and i started kicking (lightly) the driver side cat with my foot and I hear something. i was excited to think its only my exhaust and then my eye caught something moving...

Driver side oxygen sensor was loose. That was it. I am was so relieved.

So... If you have a noise make sure you double/triple check anything that can come loose. even if you haven't recently removed/installed anything.

I def suggest to get under your rig and re-torque everything once in a while.