What are the Cherokee details: lift, tire brand/type, rim offset ?? Is the alignment correct. Are the u-joints fresh ? Since both of my Cherokees do it on occasion it is not something I worry about.
Anyhoo, my sons XJ was scrubbing due to bad ball joints. If you take it to an alignment shop they'll be able to tell you...it's not a bad job with the right tools.
If it worsens and feels like the whole car is shuddering at high speeds you may have a bad joint on the transfer case shaft. It needs replacing asap if that's the case