I recently added a 4.5" AAL kit to my XJ. I started on my 1" Transfer Case drop and the first bolt I attempted snapped inside the frame so I decided to just wait until I can get the tools needed to get a snapped bolt and also to get an alignment.

So today I got the alignment done and the knocking is still very apparent and possibly getting worst. Now since I have a missing bolt holding the TC plate I am sure that could possibly be it. The thing about that is, it sounds like it's coming from further back in the rear. Possibly u-joints in the driveline or my rear drums.

The noise goes away or gets extremely quieter when I press the gas down. It really only makes the noise when I coast. It still makes the sound when I apply the brakes.

I am going to start with the TC drop and see. Any other suggestions? Thanks!

 

a lot of times, the exhaust knocks against the x-member and or the gas tank/skid.

 

I think something in my driveline is loose. I get it too. I think it's the transmission in my case.