Timing chain?

[5.0gray90']

i can hear a noise when my truck is running, its not a knock or anything major i dont think, but you can only really hear it under the truck. almost sounds like the exhaust. is this the rear timing chain making noise or something else?

 

[Big Jim M]

Us? We ain't under there!

i can hear a noise when my truck is running, its not a knock or anything major i dont think, but you can only really hear it under the truck. almost sounds like the exhaust. is this the rear timing chain making noise or something else?

You are gonna have to spend a lot more time describing the ride and the engine noise for you to get any competent answers about that noise.
Tell us as much as you can about the engine, transmission and the noise.
Also you better HOPE it isn't what you think it may be.
Big JIm