Help with grinding noise

[Dennis F]

The truck is a 2000 explorer XLT 4.0 OHV motor.

The symptoms are similar to bearings and tires, but both were changed last year. I forget the brand of bearing they are, but they were cheaper ones. I rotated the tires and the noise did not change at all. Even putting it into 4wd does not change the sound. Turning while driving in either direction has no effect on sound.

It starts around 15-20 mph and gets worse the faster I go. The sound is weird though as it has almost a high and low pitch to it as it oscillates. The pitch also gets faster the faster I go. Putting it in neutral and revving it, there is no noise so I have isolated it to driveline. It almost sounds like a thump sounds and grind/growl if that makes sense.

I replaced the bearings last year, maybe a little longer then that ago and the tires are sock sized Goodyears also replaced about the same time.

Any ideas?

 

[my pos mounty]

Could be a multitude of things.
Could be one of your "cheaper" hub bearings are gone.
Could be U-joints on your driveshaft.
Could be bearings in your differentials.
Could be either one of the CV axles going.
Coud be I missed something as well.
Does the noise seem to be coming from one direction?

 

[Dennis F]

I am almost positive it is coming from the front. The thing about the bearings though, I have heard the noise since before they were replaced, it was just very, and I mean very faint and I thought it was a tire out of balance. I never addressed it because it was hardly anything at the time. But the way it is now, it is the same behavior just amplified

Since my wife drives it and I had not been in it in months, she gave me a ride the other day and I was like, wtf?!? How long has it sounded like this? She said awhile.

It has also got progressively worse, but I will take a look over your suggestions. At least, what I can anyway

Thanks for the idea's.

 

[Florida98XLT4x4]

I have the exact same problem with 1998 XLT 4.0 SOHC 4x4 as well. I believe it is coming from somewhere in the front drivers side. I ust replaced my rotors and pads thinking it might have been a warped rotor rubbing, but no dice. I do not notice any kind of physical cues........ just the ultra annoying noise. I took it to the shop and they put it on the rack engaged the 4WD to turn the front wheels and no noise. Only when they are under pressure. But again ........... everything checks out. If you find an answer before I do then please post it.

 

[explorerguy89]

prolley uni. joint or cv axle i say

 

[Dennis F]

It was the pass. side wheel bearing. I first removed the front drive shaft and it made no difference.

Then I took apart the pass. side wheel and with the rotors off, caliper and all associated parts, I turned the hub and could feel the grinding in it.

There was no play at all in the bearing either, but the new one fixed it. I will probably replace the other side next week.

 

[my pos mounty]

DennisFdoes it make the noise whether or not the 4WD is engaged? If so, crank the wheel to one side and peek at the cv boots, look for grease being slung out of it. Also look on the back of the hub bearing for evidence of grease being slung out the back of it. If you find tears, its junk, if theres grease getting flung out of it, its junk. If there isnt any evidence, you might wanna get under the truck and change the ujoint and pray it isnt the joint at the transfercase. If it is you need a new driveshaft. Nevermind...lol, i responded late

Florida does it get worse when you turn one direction or another?

 

[Florida98XLT4x4]

OK my mystery is solved! Turns out that the shield on the backside of the rotor had been tapped at some point and was making contact with the rotor. Solution : Big-Ass-Hammer and prybar.

 

[explorerguy89]

congrats

 

[trailblazer295]

I'd suggest jacking up the corners and trying to rock the tires. The bearings could be defective and shot.