A few weeks ago my fj62 developed a noise similar to a grinding noise above 65 mph and only when the car was given enough gas to maintain speed. If accelerating or if you let off the gas, it would not make any noise. Well it started getting a little worse, and me being the genius i am decided that i would go exploring on some forest service roads close to my house. it worked great all day as i skipped between road in and out of 4wd, but as we went on the last road, i put it in 4wd and now it is stuck in 4wd. My car now makes that grinding noise above 55 and its a lot worse. Are these two things related or are they separate. I am afraid that my T-case is falling apart on me. Please give me any advise as to what to look for or what it could be. ~Thanks