I have some pretty bad grinding/growling in the front of my 2005 Explorer XLT 4-door. It is ABSOLUTELY NOT a wheel bearing. The noise seems to be coming from the front left wheel, and you can feel it when turning the hub by hand. I've changed that hub twice now (took a chance that the first one was defective), but neither made any difference. Both were torqued to 184 FtLbs per spec.

I took the outboard end of the left front cv shaft out of the hub and turned it by hand, and something at the inboard end felt crunchy. So then I pulled the shaft out and checked it over, and both sets of splines and CV joints are good. Axle shaft bearing in the differential looks good too---rolls well and no visible damage to the rollers. I'm thinking that it's got to be something in the front differential like a carrier bearing. The odd thing is that when I drove it with my Chassis Ear tool hooked up underneath, the noise was picked up at the left front knuckle, with nothing really audible from three different points on the differential case. I'm stumped on this.

Is there any safe way to drive the vehicle with the front CV shafts pulled? I'd like to isolate the front diff to be sure it's the source of the noise.

The noise does quiet way down in right turns, but the FR hub bearing was pretty quiet with the Chassis Ear hooked up. The noise starts at 20mph and dissipates above 45mph. Not like what the bad bearings on my Escape did...those just kept getting louder.

Are these Explorers known for front diff weaknesses? How can I find out what gear ratio I have, in case I decide to replace the whole unit (a used one is half the price or less than the rebuild quote I was given by a local shop).

 

Front axle internals are seldom a problem. If the noise changes in corners, it is normally a wheel bearing. If not the left, my first guess would be the right hub/ bearing ....... The nut you torqued is holding the two hub bearings together. If you remove the CV joint shaft, you would need to stick a 1 inch bolt about 6 inches long thru the spline hole and tighten the bearings so they don't wobble .......... I would also check the input shaft / pinion for movement .......... but im guessing hub bearing.

 

Well then. I was ABSOLUTELY WRONG.

Steve(ill), thanks--you got me thinking twice about the differential diagnosis. I had the extra hub assembly still on hand, so I decided to just go ahead and swap it out with the passenger side hub. Worst case scenario would be no change, so why not?

It was that hub, all right. Pushing on the wheel, I could hear/feel a clunk that wasn't there the last time I checked it. Still no obvious grit or noise while rotating the tire by hand. However, it was a different story as soon as I had the hub off and spun it in my hands---the inner bearing was dry and shot.

So, for future forum searchers with such an issue, it is possible for the sound and "feel" of a faulty passenger side wheel bearing to travel over to the driver's side. Even to the point of still sounding that way with a Chassis Ear tool hooked up. If it sounds like a bad wheel bearing, and changes noise in turns like a bad wheel bearing,...yeah. Bad wheel bearing.

 

wheel hub bearings can fail in several ways.. I have had a few go dry and squeak for 1000 miles until they are replace.... I was on the highway with our 2002 a few years ago and the front end started to wobble like a blown out tire. Pulled to the side and checked and the bearing basically failed in 1/2 mile.. I was 4 miles from a NAPA garage at the next cloverleaf. Drove 20 MPH on the berm and when I got there the tire was leaning 10 degrees inward toward the motor. Hub and bearing completely destroyed in less than 5 miles. Gouged the knuckle / brake caliper holder , tore up the backer plate... all in 5 miles !............... You never know...
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--again, front axle problems are rare on ford trucks.

 

Yikes! I've been fortunate in that the wheel bearings that I've had go bad have always just growled and lasted (admittedly) up to hundreds of miles by the time I got around to changing them. But you're right--I've seen stories of other people's wheel bearings disintegrating within a few miles of the first sign of noise/etc. I definitely drove on this one longer than would probably be recommended--glad it held together!

 

You can find your gear ratio on the sticker on the driver's side door. Hope that helps some.