I have an ‘05 FX35 that I’ve had for almost 4 years. From the time I bought it, I noticed a roaring noise that sounds as though it’s coming from the rear wheels. It’s not a constant noise, & I’ve tried everything I can think of to fix it, short of replacing the driveshaft. I’ve serviced the front & rear differentials, & transfer case, & I’ve replaced the front & rear wheel bearings & hubs. None of which fixed the problem. Could it be the driveshaft, or possibly something else??