Hey so winter is here for better or worse and I thought I'd show how I removed my fan without first removing the shroud or anything else. Possible advantages to doing this are to decrease warm up times and increase mileage due to not spinning the fan all the time. Now I realize that this is a fluid clutch fan and not a direct fan but there is still lost energy and fuel with this type. See this link for details. http://findarticles.com/p/articles/m...5/ai_57044400/

There are risks for this procedure for your engine if you overheat it so be careful and if you tow I would not do this. I accept no liability if you screw something or yourself up following my directions.
Ok so let's get started... You'll need
1/2 inch wrench
Large crescent wrench (mine goes to about 1.5 inches)
Hammer (I used a dead blow with great results)
Wire or a length of strap. (dog leash length) it will get oily though.

The first thing I did was to make sure no one would start the truck on me so the keys were in my pocket.

Loosen all the 1/2 inch bolts holding the fan to the viscous clutch. There are 4 of them. Remove 2 and set aside.


Loosen (but do not remove yet) the large fan nut by aligning the now missing 1/2 bolt space with the wrench so it installs fully on the large nut. Now knock the end of the crescent wrench with the hammer CLOCKWISE!! to loosen the large nut. IT IS REVERSE THREAD. It will take a minute or two to loosen this nut this way but it should come off. I've now done 2 this way with 100% success.


Now securely strap the fan so that it won't fall and knock around when you are removing the clutch.

Remove the last two 1/2 inch bolts from the fan assembly and let it dangle from your strap.

Now VERY CAREFULLY turn the clutch clockwise while holding it so it doesn't fall and hit your expensive rad. I removed mine through the upper passenger side.


Finally I managed to pull the fan more or less straight up and out of the shroud. Take your time though as the blades are sharp and the upper rad hose is right in the way.

Enjoy the new horsepower! Fuel economy and heat....

p.s It might serve you well to keep an eye on your temp gauge for a while and monitor all your driving habits for overheating possibilities.

Dizzel

 

Slick writeup! I have two fan hubs, one with fan and one without. I pull the shroud and fan/hub combo in the winter and slip the spare fanless hub in its place. Spring is the reverse operation, obviously. I have my radiator 85% blocked with a piece of mudflap. That plus the lack of fan keeps the t-stat from hunting all the time and heat is much better

 

Don't forget that the fan provides a small amount of airflow at idle for the A/C condenser, and if you idle for long periods with the cab controls set at a position that engages A/C, you could build up too much pressure in the high side of the A/C system and blow it.

When I pulled the fan off my 1992, I was careful to always set the cab controls to either full vent or full floor, neither of which engages A/C.

 

Good point Midnite, I have my compressor relay pulled to stop such an event.

 

What do you see for a mpg savings with the fan off? I do not tow very often at all and have thought about going electric fan which should be similar savings.

 

I have a question I have not seen asked or answered yet. What does this mod do to your intake air temps? The fan does pull air through the intercooler and cooler air is denser air. If you loose the cooler air then you will lose the horsepower that you gain by taking off the fan.

Rick

 

Interesting point Rick. I would say though that when your truck comes up to full temperature normally that the air intake temp would be the same. The fan sucks hot air off the rad in a normal operating condition and blows it all over the engine bay anyway. If I overheated my engine by not running the fan I could see what you mean about increased intake air temps but not if the engine is at a normal temp.
There is still airflow over the engine bay without a fan on even with the grill blocked off.
I suppose the only way to really know is to take the temp of the incoming air but respectfully I don't see it being a problem at all.

JP-4.5 I haven't done this mod long enough to take a mpg reading but I expect it to be a small but noticeable improvement on the overhead reading.

Dizzel

 

What I am saying has nothing to do with engine bay temperature. The air goes into the air cleaner to the turbo and then to the intercooler in front of the radiator to be cooled before coming back and into the engine. With the radiator blocked off there is also no air flow through the intercooler. With just the fan gone it would not be a problem since the only time the turbo is heating the air is during boost which means you will be moving and their will e airflow through the radiator. You can read your intake air temp with a scanner through the OBDII port.

Rick

 

MPG gain is nearly impercieveable (sp?) on my truck. Been doing it for a couple years. Airflow through the core(s) is definitely something to consider. At highway speeds, not so much, but, pulling a grade at low speeds, the fan is of parmount importance. I re-install mine and remove the blockage even in the winter if I have to haul anything.

 

A little off topic but I need opinion on a whinning noise coming from the area of the fan and don't want to start a new thread just for this.
I have a whinning type noise corelating to throttle and it sound like it's coming from the front of the engine. I have a new alternator, fairly new water pump, new A/C compressor, and a idler pulley that's got 40k miles on it. Any thought's? I'd like to fix this before something breaks on a summer towing trip.
Chuck