2004 vin 1ftyr15e34pb48594 4.0 auto, 197000 mi.
Noise from the front that is gradually getting louder. Acts like a wheel brg as it changes a bit with light rt turn input on strg wheel. Doesn't sound much like any wheel brg I've ever heard . Trying to research transfer cases and front diffs but unable to determine what is on the truck. I bought it new, so it's from the factory.Someone point me in the right direction? Haven't had any luck with free vin lookup.

 

Assuming 2004 4x4 with 4.0l SOHC engine

You have a Dana 35 SLA front axle, Live Axle(2001-2011)
A BW1354 transfer case
Torsion bar front suspension
4WABS

Does the noise change if in 2WD or 4High?

1998 and up SLA axles used a propeller joint on the front drive shaft where it connects to the transfer case, these would make a "ticking noise" when vehicle was moving if they were worn out
You can remove the front drive shaft and go for a drive, this will remove transfer case and front drive shaft as the issue if noise is still there

Each front axle has 2 CV joints, so 4 total, while not at all common, they can also wear out especially if a Boot is torn, 2 CV joints seen here: https://www.therangerstation.com/tec..._front_hub.JPG

The hubs are the most likely to wear out, and make a noise, they have "lifetime bearings" so not serviceable, lol, "lifetime" to Ford is usually 80k miles, i.e. past any warranty "life"

Also check fluid in front differential

 

The noise isn't ticking. It's a muted roar, not loud but have been waiting and watching for a few thousand miles and volume is increasing. Does not change I don't think ,from 2/4wd, will verify that. I think the front drive shaft removal sounds like a good idea, hope that isn't a big deal, I will look up a diy. Many thanks.

 

Dropped the front drive shaft and the noise is still there. If there are assurances that that isolates it to the wheel brgs I guess I should replace both. What sort of noise do bad cv joints make? They don't crack or rattle in full turn.

 

Bad CV joint is usually pop/click noise, similar to propeller joint which is a CV joint in most respects

If differential fluid level is OK then yes, replace both hubs

 

It seems like a wheel bearing to me. I had to replace my right one at around 270K miles. The left one is still good at 288K miles. I bought two new hubs so I would have one on hand if the other one starts to go bad.

You can't replace just the front bearings in these 4wd Rangers. The entire hub must be replaced. That makes it kind of expensive. You should replace the axle nut also. It is supposed to be a onetime use nut. There is also a dust seal on the inside of the hub that will most likely be broken. They are NLA and you will probably not be able find any. I got lucky and found a couple still left over. They are not absolutely needed but recommended if you do a lot of off-road trips. I do.

The best way to check if a front bearing is bad is to jack the wheel of the ground and see if there is any side-to-side movement. I observe it on the inside because it is easier to detect even small amounts of relative motion in the hub. If it is really bad you can easily detect it from the outside.