90 accord, 5 spd...i get some slight humming noises in 4th gear and tonight when i was driving home thr was a light humming noise at 2500rpm in 3rd and 4th. so after i drove on the highway and it never came back...

i know that the humming noises on autos mean that the tranny is going bad, but what about stick? i changed my MTF fluid under 5k miles ago w/ honda oem stuff...

i know my tranny is pretty worn but it still functions. another possibility i though of was maybe the brakes? although the car didnt seem to pull one way...