Posts here talk about trouble getting 4x4 to engage.
I have the opposite.
My 4x4 tries to engage without my asking it to.
Generally starts within 20-30 feet after I start the engine and drive away.
Get a terrible grinding clunking noise seemingly coming from driver side front wheel.
Usually clears itself up after driving another 20-50 feet or so.
But now am afraid to take it out because probably tearing up the splines or whatever physical system is used to engage the front drive shaft into the wheels.
This problem has never yet happened when I am driving at speed.
It only occurs just after a start and pull away from parking.
I can have a good start and drive from my house; park and go into store, come back out start up and the problem occurs.
Or it can happen as I am trying to leave my own driveway.
Took out fuse number 27 under hood labeled 4x4 module, but that didn't solve it.
The 4x4 still tries to engage.
No, I do not have different sized tires, no I have not repaired a tire.
Mine is 2004 4x4 Ranger Edge with 4.0 engine, auto transmission.
Bought used with about 110,000 miles on it.

It sounds like you have a left wheel bearing going out.The four wheel drive is switched on thru the transfer case with a electric motor. Jack it up and check the wheel bearings and CV shafts.

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barneycat11 2006 FX4

^^X2

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Thanks fellas for your comments.
As I can imagine, a wheel bearing going out would make noise all the time, not just for a few feet after a startup.
And, wouldn't wheel bearing really put up a noise fuss the faster you drove?
As I said, no noise ever develops when I am moving along at a good clip.

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Isn't there a two part process involved when you turn the dial to 4 wheel high?
1) Transfer case interaction which starts the front drive shaft moving.
2) Some mechanism that causes the front drive shaft to engage with the front wheels.
Am I right?
I am thinking something is causing the front wheels to try to hook up with the front drive shaft, even when I have not switched on 4 wheel drive.

Not on a 2004. 2000.5 and up are live axle, meaning the wheels are tied to the CVs/front axle/front drive shaft all the time. The only point of disconnect is the transfer case.

I've never heard of a truck actuating the tcase shift motor without being asked. If you really want to prove this, pull the shift motor off, confirm the truck is in 2wd, and then see if it still give you the same symptoms. But, I don't think this is necessary.

I would start by jacking the front end up and checking all the rotating parts. Is also check the fluid level in the front axle and take a look at the pads/rotors/calipers.

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WOW . . . that is very informative . . . that the wheels are tied to front drive shaft all the time. Thanks a lot !!

Someone else (offline) told me to raise each wheel off of ground separately, and holding tire at 12 - 6 position, try to wiggle.
Sure enough the left front wheel had wiggle to it. The other three were solid. So wheel bearing sounds a likely suspect.

But, I am still mystified why a wheel bearing would not make constant noise with every rotation of the wheel.

Thanks all for your comments.
It was indeed a wheel bearing.
Very strange how it was not constant, but that was the problem and it was solved with a new wheel bearing.