CV Joint? noise when turn to left or go straight

[KarstRanger]

My 99 Explorer 4WD has a road noise that sounds like mud grip tires, but the tires are not mud grip. I have switched the tires around to make sure it was not a bad tire causing the noise.

When I go straight or to the left, I get this humming road noise that increases as I go faster, but when I turn to the right the sound goes away.

It happens in reverse too when the wheels are turned the same way. It does not seem to matter if I am in 4 wheel drive or not, or if it is in neutral or not.

I just replaced the passenger side wheel bearing assembly, and that was not it. Possibly could be the other wheel bearing, as it is hard to tell which side the noise is coming from as I feel it in the steering wheel and hear it in the front floorboards somewhere. Does this type of noise that quiets when you turn one way sound like a wheel bearing?

I suspect a U-joint but how can I tell when it won't make any noise when jack the front tires up off the ground - it seems to need the weight of the truck to make the noise. The U-joints (CV joints I have been told) are sealed and I can't inspect them, but I suppose I could take the boots off.

-- Any ideas on troubleshooting this, please?

 

[my pos mounty]

Theres a few checks you can do to try to determine where the noise is, or more specifically, which component needs to be replaced.

Do a visual check on the CV joints. Check the rubber boots for any tears or rips. If you find any, replace the CV/axle.

Do the same check on the front driveshaft where it connects to the transfercase.
If you find nothing, try taking the driveshaft off the truck to see if the noise changes. If it does not, put it back on the truck. If it does, replace it.

Put the truck up on jackstands, take the front tires off and turn the hubs by hand and see if it feels chunky or if you can feel anything out of the ordinary.

If you already replaced one hub and kept the one you took off, try swapping out the other side to see if that either stops the noise or changes it.

If nothing changes with the noise after swapping the hub, and your CV's and front driveshaft checked out ok, the problem may be in the front differential (bad bearings).
You could get a whole bearing kit to replace all the bearings in the front differential for around $125 or so.

 

[KarstRanger]

That's a great idea to swap the old bearing into the other side since it is still likley good -- saving me $125. I can do that first in about 1 hour (now that I have had practice, ha ha).

I will do the other things you advise and post the results -- thank you for the great advice.

However, the fact that the noise goes away when I turn to the right doesn't indicate to anyone what part that might be that is bad?

 

[my pos mounty]

Most likely it would be the hub. The noise would change as the pressures change on it, so change that out first and see what happens.

 

[KarstRanger]

After thinking about it a bit, I think I will go ahead and buy a new hub bearing for the drivers side - rather than putting the other old hub in there. After replacing the passenger side, the noise in the front end did change (some), so maybe they were both bad -- although I sort of doubt the likelyhood of that but I don't want to take the chance, and at 140K miles, it won't hurt to have two new hubs now that I am going to abuse it more going off road more.

 

[KarstRanger]

Front end growling/humming problem fixed !!!

Well, glory be! The growling/humming noise is now gone -- I replaced the other hub bearing today (driver's side) and that fixed it. Thanks to "my pos mounty" for your advice and support !

 

[Lizard]

Thanks for coming back and describing what fixed the problem. I have the exact same symptoms and happen to have a new Timken hub lying around. This is what forums are supposed to be like. Many forums are littered with open-ended threads, then if you're lucky you can chase down the original poster for an answer. Rant over.

 

[Joe Dirt]

Lizard is right- that's the tough part on some searches- we all harp on new members to search, but a lot of the threads are open-ended with incomplete info... Thanks for finishing it, I have to do a better job at that too...