Help to leave locate noise

truck makes vibration sounding noise mostly needs to be in gear and driving. No vibration is felt in truck just a noise mostly at low rpm. Was thinking about jacking up rear and running it in gear. Should I put jack stands on frame or rear axle or both. I know it's dangerous but I would probably need to get under truck while running. Am I insane to do that or should I just take to mechanic. I've checked everything I can think of and everything under truck seems tight.

 

No lift 4x4. Doesn't go away in 4x4. Truck rides great. No check engine light. Noise will stop when I let of gas. 148,000 on truck

 

You may not hear the noise on jack stands if it’s something where the truck needs to be under load for it to happen. But I would try that, probably put the jack stands under the axle just to see.

 

dont get under it with on jacks and the vehicle in gear...good way to get yourself run over if something happens. First thing check your u-joints and Carrier bearing.