Growling, and thud from...somewhere? HELP!

[exploder_05]

2005 Explorer Limited 4.6 V8 AWD. Right around 125,x.. miles. In very good shape and had little to no problems. The explorer developed a noise that I was sure was the passenger CV shaft. It was a dull growling followed by a thud thud thud that I was assuming was the CV shaft jumping around and popping. This in no way sounds like a wheel bearing. I rolled underneath and the CV shaft are good. No play at all. Wheel bearings feel good and tight.
So now I'm baffled and jack all 4 corners and with help put it in drive and hear the thud. This happens at slow speeds. Turn the wheel from lock to lock and CV shafts have no vibrations whatsoever. Put it in 4 high and no longer notice it. Same with 4 low.
So I decide maybe its the front drive shaft. Thought maybe there was a little play in the joint right out of the transfer case. So I remove the front drive shaft. Still on jack stands and put it in gear and noise is gone. Great!?
Nope. Put the front tires back on to verify, and no more than get out of the shop and thud thud thud.
Pull it back in even more baffled now. So I removed the front diff cover thinking I'd see something bad, but nothing. No slop anywhere. Front end still lifted, turned the tires to inspect everything in the diff and couldn't see anything problematic.
HELP!
I don't see how the transfer case could be making this noise since the front drive shaft is removed, I can't imagine there being enough of a load on it to make the noise I'm hearing
Also, there was no feedback in the steering wheel and the noise happened in a straight line and turning.
Brand new quality tires about 2500 miles ago.
Anything would be appreciated!!! Sorry for the lengthy post!

 

[RogerB1]

So, what did you figure out? My 05 Mountaineer was making some light droning, rumbling sounds quite frequently. This was after getting some tires so I first thought maybe they screwed something up, but I assumed it would be a constant noise if there was something screwed up or out of balance. Then, it got worse and was a grinding, scraping noise that sounded pretty bad. But, occasionally it did sound like I ran over a stick that smacked the underside of the vehicle. At no time did I feel any vibrations through the steering wheel. After jacking it up, I found a lot of play in the front drivers side wheel when I pushed and pulled on the top and bottom of the wheel. I just replaced the front wheel bearings myself this weekend, and it drives smooth as silk and very quite.. I need to look more into this CV shaft issue that you mentioned. I hope I don't have that.

 

[Drewmcg]

I've never heard a failing wheel bearing described as a "thud". If the CV shafts are good, then it sounds like your transfer case to me--not sure what else it could be. Engine mount failures don't seem common on this truck.... I have heard of transfer cases having to be rebuilt at 125k-150k, however.

 

[07gtman]

check the front upper diff. bushing it may be so worn that the diff.is moving up and down.

 

[exploder_05]

Well I’m ashamed to say what the problem was... After three people driving and listening for the problem and all agreeing it seemed to be coming from the front half of the vehicle, it sadly never occurred to me to check the rear wheel bearings. Which is where the problem lie. Fortunately that was a cheaper and easier fix than I was starting to fear.

 

[Drewmcg]

Interesting. Thanks for info.

 

[07gtman]

Thanks..How did you come to the correct conclusion?

 

[exploder_05]

I had only driven the explorer around the yard to try to pinpoint the noise for fear of damaging something further. So after putting everything back together I drove it down the road, figuring what the heck at this point. I could actually feel a little play in the back end and it became more evident where the noise was really coming from. Guess I’ve never had a wheel bearing develop that sound so REALLY through me off. Live and learn I guess.

 

[07gtman]

I had only driven the explorer around the yard to try to pinpoint the noise for fear of damaging something further. So after putting everything back together I drove it down the road, figuring what the heck at this point. I could actually feel a little play in the back end and it became more evident where the noise was really coming from. Guess I’ve never had a wheel bearing develop that sound so REALLY through me off. Live and learn I guess.

Hey thanks again, Glad you got it figured out and, And i hope this will help other people out ..