2007 Explorer humming noise

[ryanb99]

Hi forum. I am having an aggravating issue with my wife's Explorer and looking for some advice. It is a 2007 V6 2WD. It has had a humming issue for a few months now. It gets louder with speed, but is not affected at all during turning to point to a certain side. There is also a very slight vibration you wouldn't notice if you didn't drive it daily. Also feels to me like the vehicle speed is being dragged down slightly faster than normal when foot is off the gas. No play at all when jacked up shaking wheel on any of the four wheels. It was time for tires anyway so I put a new set on and had alignment done last week. No change. I'm still almost certain it is one of the front bearings, bit I can't think of anything else to try to isolate it. At 150k miles it's probably not a bad idea to change out both front hub assemblies, but just wanted to reach out beforehand in case I am missing another possible source of this.

 

[Explorer_PL]

It can be a rear bearing as well. On mine, I have been convinced numerous time that my front hubs are bad, and it would turn out that it was the rear.
It can be also one of the driveshaft u-joints, usually the front u-joint on the front one (scratch that, you have 2WD).

What I do, I put it up on 4 jacks and put it in gear and listen to all 4 corners (again, with 2 WD it may be a little more complicated), but you get the idea.

I use a long screwdriver/pry bar and usually you can isolate the bad bearing.

 

[07EddyB]

What PL said - you CAN get a vibration in the steering wheel with a rear bearing. In fact, it can get really bad. They also don't give you the turning clues that the front bearings do until they get really really bad. I replaced my right rear bearing once because I was getting noise as well as some seriously worrying vibration in my steering wheel. My front bearings had been replaced - the rears had not and I couldn't pin the vibration or the noise to either side. Finally, the right side starting making slightly more noise in a turn. But the right front was the last one I replaced! So since I was at about 100K anyway I took a chance on the RR.

I chose wisely.

Of course, it may be humming just because it doesn't know the words?

Seriously folks - I'm here all night. Don't forget to tip your moderator!

 

[ryanb99]

Thanks for the info. I only suspect the front due to it certainly sounding like the front, but it could still be from the rear. It's honestly probably time to change them all four soon anyway, but I'd like to get rid of the problem initially by doing the front or rears first if I don't do them all at once.

I will jack it up and try to eliminate the rears as the problem at least.

 

[GeorgeH]

Does anyone know if cold weather affect bearing as they start to go bad. I.e., will the noise/vibrations be worse on cold days?

 

[Explorer_PL]

Not really, I do not thing the temperature would affect it much. After a quarter mile they are warmed up anyway.

 

[Tech By Trade]

Does anyone know if cold weather affect bearing as they start to go bad. I.e., will the noise/vibrations be worse on cold days?

Yes, if you are talking a 20 degree change. When mine were bad in the winter at -20c they would click like a bugger, but once they warmed up they would only rattle when turning away from the bad bearing.

 

[Drewmcg]

Recently I took my '02 4.0L RWD XLS into a reputable local mechanic to have the wheels re-balanced before a long trip for the holidays, due to annoying humming at highway speeds.

They called me back a few hours later and told me they were not going to re-balance the wheels, but instead were going to replace the rear drive shaft U-Joint. It did improve the humming noise (but not eliminate it). Then again, my tires are 10 years old and need replacing sooner rather than later. They could be a factor.

I'm not sure about the '07s, but on the '02s the ABS reads rear wheel speed off of a single sensor mounted in the differential. Each front hub has its own sensor. I mention this b/c, on the front wheels, an ABS warning light will trigger a DTC that identifies which wheel has sensor problems. Not infrequently, the ABS light is triggered by a front hub bearing that is going bad. So even an intermittent ABS light linked to one of the front wheels can be a clue that you have a front hub going bad. Also, hubs/bearings sometimes go bad without failing the shake-the-tire test. I recently bought a front hub from RockAuto b/c of an intermittent ABS light and a note on the above work order by the mechanic that the front left bearing was noisy (so two points of confirmation). But I'm waiting for warmer weather to install b/c the ABS is working again and the truck handles fine.

Personally, I would not replace all four hubs as preventative maintenance. There are too many things that can go wrong with the truck that would cause you to get rid of it before all four hubs fail. OEM hubs (quality Korean bearings, IIRC) can last forever--or go bad much sooner. A lot of people have horror stories about aftermarket bearings, too.

 

[ryanb99]

Sorry to resurrect a dead post, but didnt want to create a new thread. This humming noise didnt get any worse due to not being driven often so I still couldnt isolate it. This vehicle has recently become my daily driver and the noise has become noticeably louder. It is now obvious that it is the right front so I will be replacing that hub assembly as soon as I order and receive it.

My question is do you guys recommend the OEM or MOOG replacement? There are certain ly cheaper options, but I do not want to be doing this job again in 10-20k miles.

 

[dacaur2]

Either one. You will pay quite a bit more for OEM.... OEM actually uses timken bearings.... This is what I recently put in my 2010. https://www.amazon.com/Timken-HA590156-Front-Bearing-Assembly/dp/B009AA2HDO