Another "Front End Whine" Thread

[Mr_Gixxer]

My first thread so go easy on me. I know there are a few threads similar to this one floating around in the search function and I have read them all. I'm hoping I can explain my unique situation and get a different answer to my problem though so here goes.

Its a 1998 5.0 AWD Explorer. TT and shackles with 31" shoes. Bought it about three months ago with 175K on the clock. Took it to a 4x4 event about a month and a half ago and not surprisingly I broke some things. Here is the short list of major repairs done.

-Two new CV axles
-Two new bearings/hub assemblies
-Rear spider gears and axle seals
-Fuel pump
-Brake pads in front (running new drilled/slotted rotors all around)

About a two weeks after mudding and repairs I started getting a train whistle whine in the front end. The noise stays constant during movement and stops when I come to a complete stop regardless of brake pressure applied. Most days it makes the noise, sometimes it doesn't. It doesn't matter how hot it is outside.

I want to know what the chances are that its the front differential making the noise or something that was just replaced. I did get mud in the rear diff vacuum line causing it to plug up and blow my axle seals. Did I ruin my front diff? Yet?

I know its hard to diagnose particular problems no matter how much I explain them, I'm just hoping someone else may have had this same set of circumstances that could lend me some advice. My mechanic hasn't been much help.

Thanks!
-GiX

 

[Mr_Gixxer]

...crickets...

 

[eazuaje]

Sounds complicated, try explaining a bit more.

You did repaired various things so you'll have to explain a bit better.

It only happens while in motion, going front and reverse?

In my case, about two months ago I started to notice a sound while applying brakes, like a jackhammer... I stopped and checked. It turned out to be the brake calipers that were all loose... then I read about it, and it's extremely dangerous to drive like that. So I learned about brakes. Now I do my brakes and check them every now and then.

Eiber.

 

[Mr_Gixxer]

Sounds complicated, try explaining a bit more.

You did repaired various things so you'll have to explain a bit better.

It only happens while in motion, going front and reverse?

In my case, about two months ago I started to notice a sound while applying brakes, like a jackhammer... I stopped and checked. It turned out to be the brake calipers that were all loose... then I read about it, and it's extremely dangerous to drive like that. So I learned about brakes. Now I do my brakes and check the every now and then.

Eiber.

Yes only while in motion. Forward only. Turning left or right doesn't make the sound better or worse either. More like a train whistle high pitched hum than a whine I guess.

As far as the repairs go I'd think I could rule those things out that I listed above, unless someone thinks I had a botched bearing/hub job done or something. Maybe I'll get a second mechanics opinion too. Yesterday it didn't make the noise either BTW.

 

[eazuaje]

Does it go off when you brake? did you check your brake pads? they have a metal clip on a side that touches the brake disc making a high pitch sound, it ussualy softens while you brake. I use Raybestos brake pads (I won't make them any publicity), and I was in a meeting they had for customers here in a main office where I was invited; we talked about the noises coming from the brakes, harmonics, brake grease and all that stuff... I'll get the pdf to post it here, they taught us where to grease, where to push and all that... take a look at the brake pads... take down the wheel one by one and check... You actually don't need to take down the wheel, but it'll be better if you do, that way you'll know what I'm talking about.

Eiber.

 

[Mr_Gixxer]

Does it go off when you brake? did you check your brake pads? they have a metal clip on a side that touches the brake disc making a high pitch sound, it ussualy softens while you brake. I use Raybestos brake pads (I won't make them any publicity), and I was in a meeting they had for customers here in a main office where I was invited; we talked about the noises coming from the brakes, harmonics, brake grease and all that stuff... I'll get the pdf to post it here, they taught us where to grease, where to push and all that... take a look at the brake pads... take down the wheel one by one and check... You actually don't need to take down the wheel, but it'll be better if you do, that way you'll know what I'm talking about.

Eiber.

Yea I know the clip you mean. I had new pads put on when the rest got fixed too but I'll double check them. Definitely a harmonic sound. No matter what the brake pressure, heavy, light or none at all it still makes the same unchanging high pitched hum.

 

[Mr_Gixxer]

Well I just jacked the front end up to get a closer look at things. First thing I noticed was a liberal amount of dark brown oil covering the new CV axle on the drivers side between the boot on the axle and where it enters the front differential. There is enough oil that it drips down from the axle to the bottom of the differential and has covered the bottom of it. My initial guess would be blown axle seal like in the rear.

Could this be causing the noise?

I also noticed a hum in each front wheel when I would spin them coming not from the rotors (which slightly rub a little) but sounding like the new hub/bearings deeper in. Is this normal or could the mechanic have either done something wrong with the hub installation or are the new ones junk?

 

[eazuaje]

High pitch as a cow humming? These trucks have a very weak steering pump; when it's done it'll start humming no matter what. It's very easy to identify; turn your truck on, pop the hood and look at the steering pump, you'll notice any sound it makes.
In the other hand, is there oil in the axle housing? check the oil level in the differential; does it makes the sound while driving 4x4? is it AWD? High pitch metalic sounds means some bearing died, but it will also feel like knocking in the bearing housing and you'll be able to feel it in your steering wheel.

Eiber.

 

[Mr_Gixxer]

High pitch as a cow humming? These trucks have a very weak steering pump; when it's done it'll start humming no matter what. It's very easy to identify; turn your truck on, pop the hood and look at the steering pump, you'll notice any sound it makes.
In the other hand, is there oil in the axle housing? check the oil level in the differential; does it makes the sound while driving 4x4? is it AWD? High pitch metalic sounds means some bearing died, but it will also feel like knocking in the bearing housing and you'll be able to feel it in your steering wheel.

Eiber.

Well if it was the steering pump you'd think it would make that noise all the time or change when turning but it doesn't change or make any noise when standing still.

I will check diff fluid level tomorrow if I have a chance.

Its an AWD.

I literally just had all front bearings replaced with new ones 3-4 weeks ago and nothing but highway miles since then and it was making the noise a week after the bearings were replaced. Can't feel any knocking whatsoever either.

 

[Mr_Gixxer]

So I've found where the noise was coming from but don't know where to go from here without tearing it apart. It was suggested to me by my ford dealer that the noise is probably coming from the hub somewhere where the spindle (I think that's the right term) hits the hub assembly and to try spraying some penetrating oil in the gap where the two come together.

Did that, noise went away.

Tempararily.

After a few miles the sound comes back.

Any ideas what to do next?

 

[SoNic67]

How is it's U-Joint looking (by the front diff)?
Immersing the OE one in water will wash out the existing lube. You need to replace it with one that is greasable.
I just replaced on my front propeller shaft both the U-Joint (front) and the CV (rear). You are running bigger tires, so you will have that much more pressure on those.

Also, the input bearing inside the differential might suffer from immersion in mud/water. I guess that's where you did spray the WD40:

 

[Mr_Gixxer]

Nah, I sprayed wd40 specialist in the gap behind the drivers side wheel hub and the cv joint right where the axle enters the hub. It's about a quarter inch gap I'd say about 6 inches in diameter. I can take a picture tomorrow if need be.

Just found this thread...
http://www.explorerforum.com/forums/showthread.php?t=266041

Same exact scenario. Guess I'm looking at a bad dust excluder seal? I'm guessing this wasn't replaced with either the new hubs or axles?