Interesting.
Wonder if your engine rotates in reverse of every other engine made?
If it does it would require a different tranny, transfer case, A/C compressor, water pump, etc from any others ever made too.
Unless your engine does rotate backwards seems like the fan could unscrew on it's own very easily...

The reason for the left hand threads is so engine rotation works against the drag of the fan so it stays tight. My fan clutch siezed up causing my truck to sound like an airplane on the highway, if it had right hand threads I am sure it would have fell off due to the excessive drag.

I put a set of vice grips on the nut, put a couple plastic wire ties on so the impact of the air chisel did not cause them to open and hit a ciuple good shots with the air chisel, worked great did not even need to hold the pulley.

Ok, I havent had to remove my fan yet but want to get this correct for my notes for the truck in my signature.
The manual says:
(1) Disconnect the battery negative cables.
(2) Remove the fan shroud lower half. by unsnapping
the fastening tabs.
CAUTION: Do not remove the fan pulley bolts. This
pulley is under spring tension.
(3) Disconnect electrical connector.
(4) The electronically controlled viscous fan drive/
fan blade assembly is attached (threaded) to the fan
hub shaft. Remove the fan blade/fan drive
assembly from fan pulley by turning the mounting
nut counterclockwise (as viewed from front). Threads
on the viscous fan drive are RIGHT-HAND. A
Snap-On 36 MM Fan Wrench (number SP346 from
Snap-On Cummins Diesel Tool Set number 2017DSP)
can be used. Place a bar or screwdriver between the
fan pulley bolts to prevent pulley from rotating.
(5) Remove the fan shroud and the fan blade/viscous
drive as an assembly from vehicle from under
the vehicle.
(6) Remove fan blade-to-viscous fan drive mounting
bolts.
(7) Inspect the fan for cracks, loose or bent fan
blades.
CAUTION: Some engines equipped with serpentine
drive belts have reverse rotating fans and viscous
fan drives. Installation of the wrong fan or viscous
fan drive can result in engine overheating.

Now, because my fan clutch has wires going to it, I am assuming it is the elect controlled viscous fan and not just a viscous fan. So, I am assuming my mounting nut is normal (counter clockwise to remove).
Did they put two different kinds of fans on my year truck?

I am easily confused [laugh]

Counter clockwise is what it took to remove the fan clutch on my truck in the signature. Had to use a cold chisel to break it free.

You might want to try posting your question in the section of newer trucks that your model fite into, this thread is in the first gen section, 93 and older.

I wonder if they routed the belt in such a way as to change rotation on the newer models, mine was left hand threads, turn clockwise.

My Bad. Thought it had originally been posted in the Help section. Since I am not much good at this stuff, I hope I didnt hurt the thread. I notice in the manuel that it makes reference to CAUTION: Some engines equipped with serpentine drive belts have reverse rotating fans and viscous fan drives. Installation of the wrong fan or viscous fan drive can result in engine overheating. Thought that might be where the confusion with came from…. Thats a good possibility. Dont know why they would have done it but is would explain the diferences.

Thanks for the response. If and when I have to remove mine. Think I will drink some beer, flip a coin and start wailing away with something big[laugh].

all 2003 & up fans are righty tighty, lefty loosey and when re installing make sure to tighten extra cause they will unthread themselves on shutdown