2004 Ford Explorer Hub replaced but still loud noise

Honestly, I can tell you know how to check for a bad bearing. Based on what you have described, I think you got a bad one. Are you sure the noise is coming from the front? Are the tires cupped or have any shifted belts?

Hi guys. Excuse me for butting into your conversation, but if you have the hub and bearing assembly, rather than the pressed-in bearing older Fords, Chryslers, and Hondas used, you absolutely can not tell which side is noisy by driving the vehicle. I ran into this problem many times.

With the pressed-in bearings, it was common to identify the noisy bearing, as you did, by turning slightly while driving. With the hub and bearing assembly, you can make the noise louder by turning right, swear the noise is coming from the left side, and it will be the right bearing. The good news is you do not have to destroy the assembly to remove it, as you did with the pressed-in style, so you can put the removed assembly on the other side.

The only way I found to identify the noisy bearing is to run the vehicle on a hoist and listen next to it with a stethoscope. You will hear a little rumbling from the suspect bearing, but then you'll hear a much louder buzzing noise from the bad one. You won't hear it without the stethoscope because there is no weight on it.

Another way to find the noisy bearing is through use of a "Chassis Ear". That is a set of six microphones, a switch box, and a pair of head phones. You clip the microphones to various suspect points, then switch between them and listen while driving. In this case, clip one to each spindle near the wheel bearings, and clip one to the differential. Newer models of this tool have four wireless microphones and two with wires. They are all wired on the older model. Most dealerships have this tool but many mechanics have never seen it or heard of it. It is also available from the tool truck guys like Mac, Matco, Snapon, and Cornwell.

Caradiodoc

The grease is very thick. The bearing is sealed and that grease rarely leaks out. Even when it does, it doesn't spray around very much, and that isn't enough to cause a noise. When I've looked at the bearing races from the pressed-in ones that fall apart when removed, I've never seen any obvious cause for the noise.

The single worst thing you or I could do to MAKE a bearing noisy is to not have the axle nut torqued to specs when the vehicle's weight is supported on that bearing. The nut holds the assembly together. You don't even have to drive it with the nut loose. Just lowering it off the jack can do it, at least that has been my observation with GM front-wheel-drive cars. A local body shop replaced both bearings on a car they were repairing for crash damage. When they found out it would be a week before body panels arrived, they pushed the car outside, (without the engine, transmission, half shafts, and axle nuts in the car). Later, when I aligned it and test drove it, both bearings were noisy and had to be replaced again. Since then I've seen similar things happen to other people with various brands of cars.

Besides that loose or missing nut, I don't know what causes the noise to develop. It is very common on almost any car or truck today. It might be related to the fact they use ball bearings but I don't know that for a fact. We rarely had noisy bearings when they used tapered roller bearings.

Caradiodoc