Jeep Grand Cherokee

I have a 2007 Jeep Grand Cherokee that I absolutly love, but lately a I’ve been noticing a problem with it gradually getting worse. When I am on my way to work in the morning, and I get on the on ramp to the highway, as I start to accelerate the back end of the car starts to make a rumbling noise. When I look at my gauges the rpm’s are going up and down kind of like it doesn’t want to shift. The only other time I notice this is when I try to climb a hill on the road or highway. There is no check engine light on. I have had this problem for quite sometime, but just recently noticed it because it has gotten worse. My husband has had a few mechanics drive it, and has asked a few others about it. They either don’t know or have a very wide range of things it could be. My friend I work with had a Pontiac Grand Prix. She said that her catalitic converter plugged up and caused her transmission to go out. Thank you

At what speed does this occur? Will the Jeep accelerate OK on level ground? Does the yellow ENGINE light ever blink on when you are driving?

Are you in 4wd, try 2wd if so.