When I put my truck in reverse it sounds like a hundred crickets are chirping under my truck. Any of y'all seen this?

 

Update to this. Only happens when the truck is cold.

 

I would first check exhaust system most likely something loose possible clamps or exhaust pipe rubbing on frame. Missing bolts to exhaust sensor tubes at the DPF #1





1 - TUBING SUPPORT BRACKET 5 - DOC TO NOx ABSORBER CATALYST (NAC) FLANGE
2 - FLEXIBLE PRESSURE DIFFERENTIAL TUBING 6 - NAC
3 - TURBOCHARGER CLAMP 7 - NAC TO DPF FLANGE
4 - DIESEL OXYGEN CATALYST (DOC) 8 - DIESEL PARTICULATE FILTER (DPF)

 

I will check on the bolts this afternoon. Thanks for the idea.
Only problem is it seems that a pack of wild squirrels climbed out of the tree took my tools and stole my pipe and left me with a turbo back straight pipe.

 

That explains it most likely squirrel got stuck in your straight pipe, floor it a few times should dislodge him.

 

Gold star for you bigiron70. I can admit when I'm a tard.

Because my squirrels used a pipe that would not use the factory front hanger just behind where the cat is suppose to be I'm getting a vibration.

I had someone hold down the truck while I crawled under in gear. The pipe is actually vibrating so much it's creating a harmonic noise.

 

Chrysler is hanging weights on anything that might cause a harmonic vibration. They use aluminum on many parts to try and cut the weight down then they turn around and hang iron on just about anything that could vibrate and cause a noise. Go Figure.