Underbody howl

[timmccmd]

Have 2002 Eddie Bauer 4x4 with the V6. 150Kmiles. 4x4 function hasn't worked in a while (I believe the transfer control module is out). Have had same tires (combo off-road/road SUV) for some years now; tread doesn't seem to wear much but the tires are 'stiff'; ride is very firm. Lately there is a howling noise that presents itself at about 15 mph and increases in intensity as speed increases. Since tires are so stiff, there has always been some road noise; at 50+mph I can't distinguish which noise is which.

Had one Ford technician tell me I had a front hub going out. That was 30+ miles ago and no failure of the bearing yet. Plus there is no smell (metal-on-metal), no evidence of high heat build-up at any of the four wheels. No vibration; no issues with steering and no change in mpg (still lousy as always).

At times I think noise is front transfer case; maybe the split axles. Other times I wonder if its the differential and noise just propagates forward.

Any ideas, thoughts, helpful. Thx

 

[Number4]

I've not read much about front cases making noise. Noises in general can be deceptive in which direction they are coming from. I would have someone else drive the car, then have you sit in the back, center. This will let you properly detect where the noise is coming from. Front or back.

Front hub bearings don't fail like cone bearings. As these go out they tend to howl. Mostly on turns. So if it is your bearing and it's always howling, you are on borrowed time.
When they fail, they don't wobble, by the time they do wobble the damage is pretty advanced.

 

[timmccmd]

Thanks for insights. Doesn't howl any more or less on turns. Mainly notice on straight-away driving. What keeps me from certainty about hub and bearings is no smell, no heat, even after freeway speeds (yeah, I know, somewhat dicey). Should be metal to metal by now; hot and smelly. None of that after driving. I've now put 100 miles on this since being recommended by Ford tech that hub was about to fail. I like your recommendation about having someone else drive. Should have thought of that myself.

While on the hub, anyone ever figure out why did Ford try to make this as an assembly which has to ber replaced as a whole, rather than allowing repair just on wheel bearing? I do find bearings on autoparts websites, but the replacement of bearing-only looks about as difficult as changing whole hub.

Thx

 

[Number4]

These hubs don't have bearings as you know them. This bearing design (originated on imports I believe) is much better than older styles.

I don't know that your going to get the symptoms you are looking for until they have severely degraded. Quality of the unit probably playes in how it breaks down as well. You could potentially drive another year with a bad bearing, but I wouldn't recommend it.

A howl noise on these Explorers is almost always a wheel bearing, or the rear diff.

http://www.skf.com/binary/79-147232/457284.pdf

http://www.skf.com/ca/en/products/v...nd/hub-bearings-and-kits/premium-quality.html