i dont know if this problem has been addressed in a previous thread, did a search but came up with nothing, please direct me to the thread if i am wrong

i hear a whining/humming type noise when driving in 1st, 2nd, 3rd, and overdrive, everything is fine in 4th gear, i have a 92 ranger 4x4 2.3l engine 5sp, this has been an issue for a while but seems to be getting worse/louder, i just had my clutch replaced along with the slave and master, an entire clutch kit was put in so i have a new throwout bearing and i have heard a bad throwout could cause this issue, what are other possibilities? the noise seems to be coming from the transmission area...........