Hey guys, new to the forum and looking for some suggestions. I have a 2012 GMC Yukon with roughly 140,000 miles on it and about a year ago it started developing a loud tick/tapping noise from the bottom of the engine. I was told possibly exhaust manifold gasket...replaced those. Still nothing. Weird thing is it only happens in drive or reverse...while moving...or with the foot on the brake either in drive or reverse. I hear nothing when it is in park or neutral. I will upload a video to YouTube shortly. Any ideas??

Here is the link to the YouTube video. Forgot to mention it has the 5.3 vortec.
https://youtu.be/Fh4-TFFjY5k

Here is the link to the YouTube video. Forgot to mention it has the 5.3 vortec.
https://youtu.be/Fh4-TFFjY5k

did you check the flywheel?

I took both inspection plates off last night but can't get a really good look at it. The parts of the flywheel that I did see didn't have any cracks or anything.

looking through the larger hole look towards the center of the flywheel. usually they crack from the center out to one of the holes in the center of the flywheel,not to the edge with the ring gear. you may have to turn the engine over to see all the way around. you can use a screw driver to turn the flywheel through the larger hole that your looking through. I suspect the flywheel because in drive and reverse your loading it and in park or neutral there is no load. the engine doesn't appear to make any abnormal noise out of gear. hope this is helpful.

I appreciate the info dpieroni3. I called and got an appointment at the dealership for Tuesday. Didn't want to bite that bullet but hopefully they can find out what'* causing it. I will keep you posted.