I recently bought a 98 XJ. It came with 35" tires, but I am replacing them. Because of this I put on stock tires just for now, but when i went to move the jeep (not even putting gas on, so it was just crawling on flat ground), it has this hard rumbling noise and shakes somewhere in the front. It never did this with the bigger 35" wheels. When I looked at the front driveshaft, it seemed to not be rotating smoothly, but instead chattering while it rotated. I'm not 100% sure though because I went out there again to see what it was doing and it wasn't chattering but still grinding.