Hi everyone, after installing a new muffler on my jeep. I noticed it started to make a grind then a repetitive clunk when I first start to accelerate. The clunks mostly happen at around 1-10 mph and then go away. Occasionally it will make a grind sound while driving fast. The sounds only occur at lower rpm’s. In park the grinding sound also occurs.

I’ve ruled out U-joints because I just replaced them.
I was thinking it could maybe be the exhaust coming into contact with the frame somewhere but not sure.
Any other suggestions would help. Thanks!
I attached a video of the sounds it makes.

Thank you for the response! I’ll have to check that out later. 👍