Exhaust pipe rattle

Something under truck is making a rattling, sometimes rubbing noise when driving on dirt or rough roads. I crawled under and shook ever thing and the only thing I noticed is when I try to push or shake the muffler, the exhaust pipe knocks against the frame a couple inches forward of the muffler and there is almost no clearance there.

what normally prevents this from happening? I cannot tell if a clamp or bushing is missing, but nothing appears broken or loose.

I hit a football sizer rock in desert at 10-15 mph a couple weeks ago and that is when this noise started. It shook the truck real good when I hit it.

 

The exhaust pipe may be banging against the composite bed where the large upward curve is at to avoid contact from the solid axle. If it is only happening under uneven roads that generally jar the truck around it is going to be that.

Either that or you hit something with your exhaust so hard that it tweaked it somewhere that it should not be tweaked.

 

Definitely "tweaked " something because no noises before I hit the rock; I had been camping off road so would have noticed it.

 

I got around to taking a photo. The exhaust pipe is just about touching the frame, maybe a couple millimeters gap is all. I am thinking a heat shield could be squezzed in there to prevent the rattling.

Update. Took it to muffler shop today. A tailpipe hanger got pushed by the impact and flipped around so it was applying upward pressure shoving the tailpipe against the frame. No charge, which is why I waited so long as I know the guys at my local muffler shop.