My 1998 4Runner limited edition has 160,000 miles and has never let me down on or off road in the Blue Ridge Mountains of Virginia. Recently while driving in town it hesitated when starting from a stop and then jumped forward a bit and as I was merging onto the interstate , it refused to move forward completely. I was able to drift off the side of the road and the engine continued to run but would not engage movement forward or back. I shut off the engine and had it towed. My regular mechanic said the battery had shifted loose somehow and that was the issue. I had looked under the hood and did not notice any unusual issue with the battery and I think that happened when it was towed. He reported driving it around without having a problem. Now I am concerned taking it off road in the mountains where there is no help or cell phone service. Any idea what could have happened?