I have been trying to chase down a whirling noise that follows vehicle speed since I bought the truck in my sig in Oct. The noise happens whether or not the hubs are free or locked so I don't think it is the front needle bearings. I just changed the transfer case fluid over to Mobile 1 Syn. and there was no change in the noise. I also changed the front pads, rotors, slide pins and calipers a few weeks ago and that didn't have an effect on the noise either. Today I took the truck for a ride and I'm not sure but it seems almost like the noise is a bit louder! And I noticed that if I hit the brakes firmly, harder than a normal stop the noise gets significantly quieter and if I release them again the noise goes right back to normal. This has got me stumped...
Along with this noise, I have a vibration on the freeway that gets worse around 55 and lets off around 61. Its worse at some speeds and better at others. Thinking the two were related I pulled the rear drive shaft and checked the u-joints and the carrier bearing for play. The carrier bearing doesn't have any real play but there is quite a bit of slop, ability to turn back and forth, where the driveshaft comes out of the transfer case. All but one of the u-joint cups were fine. The bad one isn't even too bad just the rubber seal around it is a little off, there is still grease in it and the needle bearings seem fine.
I am at a real loss so sorry if this is long and circuitous. I really need some help!

 

Have you jacked up the front end and checked the front wheel bearings yet?

 

checked them how. I have had both ends up several times

 

Take the wheel and try to move the top and bottom inward and outward.

 

no movement, that's how I checked the ball joints

 

Have you had the tires balanced? or is there cupping or uneven wear on any of the tires?

 

Had the OEM General tires developed cups on the front tires and they were noisey.. Replaced them with Michelins.. quiet ever since.. Try rotated your tires just for fun..

 

withj all the fluid changing, did you replace the power steering fluid?

 

I have rotated the tires, which are in really great shape actually, no difference. This is a noise that only seems to be affected by vehicle speed. I have not replaced the power steering fluid, but it is at the proper level and I know thats not the problem bc I have pretty loud ps steering whine in addition to this other noise the OP is about.

 

X2 on power steering fuild. It runs the brake booster. Flush and use Mobil 1 syn. ATF not power steering fuild. This mit help!

 

Could it be a noisy belt tensioner?

 

maybe the pinion bearing? i had one get bad in a mustang. it made noise until i got on the brake hard. it got pretty loud too but it wasnt competing with a 7.3

 

You can have a bad wheel bearing without them being sloppy.
Try driving on a deserted stretch of road and swerving back and forth hard enough to unload the inner race of the front wheel bearing, similar in fashion as if you were driving a slalom course.
If the noise goes away momentarily, then it's a bad bearing on the side that you are turning away from.

 

I had the same problem. It was a bearing going dry.
If you have front ABS, you can try greasing through the pickup hole as someone posted. Do a search. I replaced the hub anyway. Problem solved.

 

I don't see how this would be a powersteering or brake booster issue...
The belt tensioner is brand new I just replaced it, the belt, and the idler pulley, also can't see how this is applicable....
Kwik, I'll be hard pressed to find a road around here to do this but it's nice outside so I guess i'll go for a long drive today, thanks for the help. I'm not sure the noise is coming from the front though...sounds like it is from behind the front seat....?
I wish I had an ABS hole to grease through, darn 99.5 xlt's...I have been slowly putting parts on the truck since I got it and the wife is getting a bit fed up on our budget so I may just be living with it for a little while if I do have to do the bearings...