car starts to whine after about 30Km

[nff]

i will try to get a video as soon as possible but here's the scoop:
after driving for 15-30km a whine starts up i'v checked all the wheels and they are all tight and dont make noise when i turn them. i wonder what would cause this?

[ctbrighton]

still could be the wheel bearings, or either diff, or any number of bearings in the rear casing of the trans lol time to jackstand it on all four and get brave with a large screwdriver and put your ears to work.

[nff]

its the transmission it has a leak around the back and was really low on oil. i topped it up but the noise is still present.