what is clunking noise on acceleration and deceleration

What is your question?

clunks sometimes on acceleration and deceleration and at certain speeds sounds and feels like 4wd low is engaging. when traveling at hwy speed it seems like 4wd is engaging. shifted into neutral and problem still there as it slows down the jeep

What makes this problem better or worse?

worse after 15 mins of driving

How long has your 2012 Jeep Grand Cherokee had this problem?

a week