Rumble Strip noise

[photog22]

I have a 2005 Ford explorer. I've had several issues over the past few months, which I think have all been taken care of except one. It started with horrible vibrating and shaking while driving at high speeds, which was due to bad u-joints and an out of balance drive line, which have been fixed. I still had some vibrating after that so I took it back to the shop and they replaced my shocks/struts. Tires have been balanced twice, and rotated. I still had a grinding sound coming from under the left front tire so my husband replaced my wheel bearing on that side. The grind is gone but when I hit the highway and go around 70-75 my car makes a rumble noise. Like if you'd drive over a rumble strip on the highway but there's no vibrating associated with the noise, it's just a noise, and it's pretty loud. I spoke with my uncle who is an experienced mechanic (50+ years) but he didn't have too much to say without looking at the car, as he lives in Montana and I'm in Nevada. He mentioned it could possibly need a front end alignment but I told him there's no play in the wheel, it doesn't drift while driving it and it drives fine except for that awful rumble noise. ANY ideas at all? I have to take it to Montana in August and I want to make sure I'll be good to go before I leave. TIA

[shorod]

It's possible the noise could be due to tires, but it's also possible that the noise could be yet another bad wheel bearing. Does the noise change if you change lanes? Does the noise seem to go away or get worse if you lightly accelerate or let off the accelerator?

-Rod

[photog22]

I don't know about it changing with moving to different lanes because I live in the middle of nowhere, there's only two lane highways here. It does go away if I let off the gas. If I'm at 70 mph or above I can hear it but as soon as I let off the gas and it goes below that I don't hear it anymore. I'm not on the highway much because to go anywhere from where I live is at least a 3 hour drive. The last time I took it out on the highway I noticed it starting at 70 mph and it gradually got louder the faster I went but not drastically. It goes away below 70 mph

[shorod]

Sounds a bit like the standard rear-end noise that probably 85% of the Explorer owners notice and comment on. Some people have tried a different weight of rear gear oil with marginal success, some people have had the rear ends rebuilt, again with marginal success. Most just live with it.

You should consider changing out the rear gear oil and using the proper additive if your differential is a limited slip. Make sure to refill to the proper level. See if that changes the noise. Hopefully it won't make the noise apparent at lower speeds. While under the truck changing the oil, inspect the universal joints to make sure they don't show signs of having leaked out the grease.

-Rod

[photog22]

Ok thank you for your help. I'll be sure to let my mechanic know what you said. I took it in this morning but they didn't have time to look at it, so I'll be going back on Monday. I hope it's not something I have to live with because it's quite annoying.

[photog22]

So everything has been looked at by two mechanics, and both said the car is mechanically sound. They both seem to think that the noise is tire/road related. I do have cracked ball joint boots on both front sides, do you have any idea how much that is to fix? Or is there something I can do to keep dirt and rocks from getting in there while I drive to Montana? It's a 9 hour drive from where I live