Hello, i have problem with my lancer evo IX GSR, basically is a loud noise coming from the back like a worn bearing, it is speed related, just over 40mph, it not change or intensify when i turn left or right. The noise change only if im cruising with a little gas, the sound become swinging. With no gas, pulling or decelerating the sound is constant, and increase with speed
I checked and changed the rear diff oil, with no noticable problems, no leaks or anything related, the wheels bearings seems in good conditions, the only thig i've found is on the rear drive shaft, seems a little loose, like 1-mm of clearance up and down on the diff side, where the axle is attached
it is possible is this the problem?
i tried to upload a video but doesnt allow me
thanks, Luca

 

put up on a lift... run it in gear and see if you can hear it.

 

could be diff input pinion bearings