For long time I thought it was my belt going bad and that it was making a supercharger type sound, but then we replaced it and it is still making the sound. And recently discovered the sound goes away when the torque converter locks up in 4th gear..... so guessing its something to do w/the transmission? The sound doesn't bother me, it sounds like a supercharger type whine, so I kind of like it, but anybody have an idea what the sound I am talking is? Maybe torque converter? I have no clue yet.

 

Might need to start narrowing it down a bit more, does it make the sound in Park/neutral? if yes its something forward of the transmission. if no does it increase in frequency with speed? where does it sound like its coming from? if its toward the rear of the car could be a bad u-joint or something in the rear end

 

I don't hear it in park or neutral, and think sound is coming from the engine bay(could be wrong, sound could be maybe from transmission, but not the rear of the car). Just while its in gear even at 0mph, but then goes away once you reach torque converter lockup in 4th gear. And sounds like a supercharger whine would.

 

ok so you have already isolated that it is probably the transmission. I see you have had yours rebuilt previously and some other issues and fixes with the transmission, so I will have to defer to the auto transmission experts as I am definitely not that. Just trying to help narrow it down. I am assuming you have checked the fluid and its full? how does the fluid look color/smell wise? could pull the pan and drain fluid completely as the next step and check for metal etc and inspect things.

 

mmm yeah something to do w/the transmission for sure. if I had to guess its the torque converter making a whine sound. It doesn't bother me, I sorta like the sound, and its been making that sound for years and years, as long as it works.