You said that you just swapped the CV axle. If you don't have correct torque on the nut it could be loose and making the humming metal to metal noise. On the same note - you can't just crank those nuts down as tight as you'd like em either - the torque spec is there to properly load the wheel bearing. Too much and you distort the races and mess the bearing up and too loose? It'll make lots of noise and drive you crazy.
HENRY
95 Contour, Custom EVO bodykit, 2.0l, PNP Focus head, Stage 2 cams, Je pistons, Eagle rods, 4in1header, 2.5" header back exhaust(complete stainless), D P nitrous, ram air intake, 10mm wires, flamethrower.
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