I'm also experiencing the same problem. Motor whine's right around 60mph and quiets down at around 75mph. Not sure what it could be. I was told it could be the alternator, timing belt, PS pump, water pump, fan belts. Looks like I'm going to have to take it in and get it looked at. Although I do have a leak in my PS steering pump and I just filled it up with Lucas PS fluid with the stop leak and the noise died a little, but the noise is still very loud. Any thought's? Btw, I drive a 92 4runner with 200k miles. V6 (3.0) 4x4.