[harry_the_mechanic]

I got a 1995 s-10 blazer with 158,000 miles on it, I hear a grinding noise when its in gear, but the noise goes away in park or in neutral. The noise gets louder with engine rpm. It happens even when the truck is NOT moving. It cant be any of the pulleys or accessories cause it goes away in neutral or park. I did compare to the howling sound that comes when its in 4-HI. The noise is different than that, besides the howling sound goes away when i switch it back to 2-HI, which is normal. so what you guys think about this???