I know that this issue is fairly common but my particular problem is more unique then others I've seen on this forum. A couple days ago I shifted my (2004, Automatic) Ranger into 4x4 low to park in some practically stormy weather. Once I parked I switched to 2 wheel drive but the 4x4 indicator light was still on. Ever since then I've been dealing with a barrage of problems. First off my engine is much louder and seems to be grinding on something. I also seem to accelerate more slowly. (I don't know if this just an effect of it being in 4x4 though). What worries me most though is that whenever I go above 10 MPH the truck seems to buck. I thought it was just shifting gears at first but when I put it in drive without touching the gas or break, it will constantly buck forward. My back wheels will also occasionally bump as if they rolled over something, witch they never did before.
I've tried putting it in neutral and shifting back to 2 wheel drive but nothing happens. Is there any way to fix this without breaking the bank?

 

Welcome to the forum

In 4low engine will be louder, higher RPMs, and on paved bare roads wheels with bind and truck will buck as binding up is released
You should drive in 4WD on paved bare roads, just on dirt, gravel, snow or ice

You will need to get under the truck and remove the 4WD Shift motor, 3 or 4 bolts, to see the actual position of the transfer case

Picture of the back of transfer case and shift motor: https://www.therangerstation.com/tec...t_motor-19.jpg
Red arrows are the bolts to remove
Blue arrows are 4 bolts that may need to be removed to take off a vibration damper install in some year, look like a hockey puck

Yours will just have the 7 wires, no green or brown wires as seen of picture

Once shift motor is off you will see this: https://www.therangerstation.com/tec...ft_motor-2.JPG
Thats the transfer case shift rod that the shift motor turns to select 2WD(2H), 4wd(4H) and 4low(4L)

In the picture its pointed at 2H(2wd)
You can turn it manually with pliers, BUT..................make sure one tire is BLOCKED or vehicle can ROLL AWAY even in Park

While shift motor is off and plugged in to its connector, look at where its drive shaft is pointed
Turn on the key, engine off
Select 2WD, 4high and 4low and check shift motors position each time, to make sure its moving and stopping where it should

There is a fuse in engine bay fuse box that powers the shift motor, fuse 27(20amp)

2001-2005 Ranger 4x4s are known to have the 4x4CM(control module) fail, in 2004 its behind the radio, you should HEAR IT "click" when you change the dash switch to a new position, thats from relays inside the 4x4CM
If 4WD lights are still working and you hear the "click" the 4x4CM is most likely OK