98 Explorer Problem - CV or Hub?

[njones1220]

This is my first post here, and after looking around it seems I'm in the right place for knowledgeable folks who can help me avoid wasting money on a mechanic.

I don't take my truck in for anything unless it's absolutely something I can't do on my own, because it's too damn expensive. Now, for my problem.

I have a 98 Explorer with 4 wheel drive that recently started making a noise from the front passenger side. The best way I can describe it, is it sounds very similar to when you're driving in 4 wheel high, or live when you drive on a freshly milled road that hasn't been paved yet. It's a growling/howling noise that doesn't become noticeable until I hit about 25-30, and it gets louder the faster I go. When I decelerate, the noise slows down, but seems to get louder.

This has only been going on for a few days, but I've done every check I can think of without taking things apart. I jacked it up, shook it at 12 and 6 to see if there was play from a bad hub, and it was solid, absolutely no wiggle at all. So I'm thinking it probably isn't the hub/bearings, even though google would like me to think otherwise.

I admit I know nothing about CV joints/axles but I did learn more than I cared to after this problem developed. I'd hate to have to take them out to check them, so I was wondering if it was possible to tell from looking at them still on the truck. I took a picture of the driver side one which appears closed or compressed, and the passenger side where the noise is looks more expanded or open. Neither boot has a hole, tear or grease coming out. I was more or less wanting to know whether they are supposed to look like this, or if it's a fair assumption that the joint on the passenger side is screwed. The mechanic by my house told me $250 if it's bad and he replaces it, but I'd rather go with the under $100 I can do it for.

Any opinions, or could it be something different entirely? The pics were taken with a straight wheel on level ground. Oh, and there was never any grinding or metal on metal or dragging a chainlink fence sound like others online describe.

 

[Turdle]

One thing to note. On the "closed" side the clamp band on the cv boot is inside the sway link, in the "open" picture the band is outside the sway link. The position of the smaller clamp could be to blame for different compression of the boot.
Considering the noise you described, I still think it is the hub. Be sure to check the driver side hub also.

How does the front diff feel if you were to jack up both front wheels and rotate them? If you can have a helper hold one wheel while you rotate the other you should get the differential gears to work. They should feel smooth.
Also, be cure to check the front differential fluid.

Check the brake caliper bolts, and the caliper bracket bolts, sometimes they can work loose.

I hope this helps. Still betting on the hub though.

 

[Kevlar7R]

I would suggest jack up the passenger side only, and rotate the wheel by hand. Listen for hub noises, but also put your hand on the back, stationary part of the hub and feel for grinding within the hub.

Pull the abs sensor and look at the end of it. It should be clean. If there is a build up of goo and/or metal on it, clean and reinstall, but hub failure is suspect.

If it passes both of these, then you've eliminated the hub. Grab the portion of half shaft between the 2 cv joints, and feel for play. Usually, cv joints leak before they fail, but not always. Half shafts are really not that hard to replace if you're somewhat mechanically inclined. They also tend to fail in the way you described.

Another possibility is the bearing within the diff where the half shaft goes in. With the half shaft out, spin this bearing with your fingers and feel for rough spots.

When was the last time the front diff fluid was serviced?

 

[njones1220]

One thing to note. On the "closed" side the clamp band on the cv boot is inside the sway link, in the "open" picture the band is outside the sway link. The position of the smaller clamp could be to blame for different compression of the boot.
Considering the noise you described, I still think it is the hub. Be sure to check the driver side hub also.

How does the front diff feel if you were to jack up both front wheels and rotate them? If you can have a helper hold one wheel while you rotate the other you should get the differential gears to work. They should feel smooth.
Also, be cure to check the front differential fluid.

Check the brake caliper bolts, and the caliper bracket bolts, sometimes they can work loose.

I hope this helps. Still betting on the hub though.

Definitely going to check this all out. I would just really hate to replace something I didn't have to.

When was the last time the front diff fluid was serviced?

Never, until last April. I bought this truck last year from a lady who was the only owner, and I've done nothing but replace things she neglected for over a decade. Nothing major, just a bunch of minor things that add up fast. Fuel filter, MAF sensor, EGR valve, transmission filter, IAC valve, PCV valve, fuel injectors, tie rod ends.........now this. I don't mind doing it, I just like knowing I'm replacing something that needs replacing.

 

[njones1220]

So I jacked up my truck, and both wheels spin freely. There is no noise from either wheel at all, no play up or down on either wheel, and no grinding or clunking feeling when I spin the tires with my hand on the hub.

However, I tried the driving backwards in a circle trick, nothing unusual happened. When I started driving it forward, it was groaning loud, and would go away completely when I made a right turn.

I got to thinking - about 2 months ago, my truck started to vibrate when I'd be driving between 40-55 mph, but it wouldn't do it at higher or lower speeds. That seemed to stop about a week ago - a few days before this new symptom. Are the two related? Does this mean the hub is the issue? Is there any way this can be related to the 4 wheel drive?

 

[Turdle]

Is your truck a v6 4wd or v8 AWD?

 

[njones1220]

V6 4wd

 

[njones1220]

I took it to the mechanic this morning for a diagnosis, and he seemed extremely puzzled. He said he didn't want to put a hub on and it not cure the problem, but he never said whether the hub was good or bad. He said the CV is definitely fine, and he thinks the problem might be in the front differential. I just can't remember if he said pinion gear or pinion bearing.

 

[Kevlar7R]

Noises can be misleading when you're hearing them from in the truck, but you said the noise was passenger side. The pinion is basically right under the drivers feet. There are a lot of other bearings in there that could make noise.

Also, the pinion bearing is unlikely to make much noise when you are in 2 wd. You could try taking out the front driveshaft and see if there is any change. If it changes significantly, then it is definitely something in the front diff.

 

[njones1220]

It's definitely passenger side. I rode in the passenger seat and had my wife drive, and you can even feel it under the passenger floorboard.

 

[Kevlar7R]

It's definitely passenger side. I rode in the passenger seat and had my wife drive, and you can even feel it under the passenger floorboard.

Your wife was driving? How could you hear it over the screaming..... Your screaming. Lol

 

[Kevlar7R]

Go find a dirt road and drive the same way, but in 4wd. Is the sound the same?

Also, try driving the same speed, but in a different gear (perhaps 2nd) and see if it's the same. Does the sound change at all when the transmission shifts?

The reason turdle asked which truck, the awd ones have another cv joint in the front drive shaft, and it sounds a lot like what you're describing when it fails. However, if im not mistaken, your truck has u-joints, not a cv joint.

 

[Turdle]

Oh! I think I have a good question.

Do the front tires match as far as brand, size and wear? Different brands might make a big difference. Wear pattern could even create a difference in rotation speed. Just throwing it out there.

 

[njones1220]

Your wife was driving? How could you hear it over the screaming..... Your screaming. Lol

Oh trust me, there's a now a permanent pucker mark in the seat

Go find a dirt road and drive the same way, but in 4wd. Is the sound the same?

Also, try driving the same speed, but in a different gear (perhaps 2nd) and see if it's the same. Does the sound change at all when the transmission shifts?

Gonna go do this right now, I'll let you know.

Oh! I think I have a good question.

Do the front tires match as far as brand, size and wear? Different brands might make a big difference. Wear pattern could even create a difference in rotation speed. Just throwing it out there.

Yep, just bought a full matching set of Goodyears last month.

 

[njones1220]

In 4WD, 2nd gear and regular it did exactly the same thing - exactly at 20mph, the growling started from the front passenger area, and got louder the faster I went.

 

[Turdle]

I would shoot the cheaper bullet first and replace the right front axle bearing and seal. Not a bad idea since chances are they are original. In doing this you will actually be able to feel the cv joints, and spin the hub by hand.


2nd shot would be the hub.

 

[GJarrett]

Try Jon's cheaper bearing/seal idea first... but I'm voting on the hub too, FWIW. I've used up several - especially after I went to 35" tires on ol' Herc - and that's what one sounds like when it goes south. When my CVs start going bad they usually start a sort of clicking noise at first, not grinding.

It is possible when you raised the tire and spun it by hand, that by releasing the weight of the vehicle, you freed up the pressure on the hub enough to allow it to feel okay while playing with it. It could be something else, but my money's on the hub... if you are sure the sound is coming out of the right front and not from the middle. What puzzles me is no play wiggling the tire 12/6 o'clock; there should be some looseness with a bad hub. That's probably why your mechanic starting wondering about the front diffy.... which would be the next logical suspect.