Ok need a little advice it snowed 3 inches here in Tenn today. Had to lock my hubs in on my 2000 f-350 I replaced my hubs last year with a set of warn hubs. Going down the road with the front end locked I get a rumble sound from the left front I can take it out of 4wheel drive and I still get the sound in my left front . My u joints are in good shape everything I've looked at appears good when I unlock my hubs everything is quite.
It has to be the front axle does it not what do you think.