I finally got around to replacing the stock clutch fan with a SPAL electric fan. I used a SPAL medium profile 16" fan and a SPAL PWM electronic fan controller.
This mod took longer than I thought it would, but it was still way worth it. Now the engine doesn't ROAR to life like it used to. It starts up nice and easy. It's really amazing how quiet the engine is now. I can almost here crickets chirping in the background. LOL
The engine also seems to have more pep. I don't have any dyno numbers, but I'm pretty sure that the engine accelerates and "winds up" faster, because it doesn't have the extra load of having to spin the fan, and also the resistance that is created when the fan is moving air.
Since the fan doesn't come on until the coolant gets warm, the engine now warms up quicker, which is nice on a cold night like tonight. It only takes a few minutes of driving to get it up to normal temp (185 F). It's certainly quieter than the stock fan, especially when the fan controller has the fan running at half speed.
If for some reason I need to go through deep water or mud then all I have to do is open the hood and turn the thermostat up to 240 degrees, and the fan will shut off; then I don't have to worry about water or mud tearing up the fan.
Now for the install details:
I removed the grille so I could get a little closer to the engine for reaching down in there. And for mounting the thermostat control.
Take off the engine cover.
Take off the 8 plastic pins that hold the trim piece on top of the radiator and core support. Pop up the center part of the pin with a flat head screw driver.
Pull off the little hose on the reservoir.
To get them out you have to remove the fan and the shroud at the same time. I used a ratcheting wrench to take off the 4 nuts that hold the fan on. I took off two nuts and then started the engine for a second so that the other nuts would spin around to the passenger side of the engine, where they are easier to reach. Just let the fan sit there. Then take out the two bolts that hold the shroud at the top corners. That is all that holds the shroud. The bottom part of the shroud fits into clips on each side. Just pull straight up, and bring the fan up with the shroud at the same time. There is a little nub at the bottom of the shroud that gets hung up on the bottom radator hose. Get under the front of the truck and squeeze the hose and then push up on the shroud. Now it should all come out with a little manuvering and some sweet talkin'.
Put the 4 nuts back on the pulley. The bolt studs aren't threaded all the way because of the mounting flange of the fan/clutch. So you now need to use a washer on each stud to work like a spacer. I then put red Loc-tite on the threads and tightened down the nuts.
To make the fan as efficient as possible you need to seal off any space on the sides of the fan, so that the fan can only pull air straight through the radiator. To fill in this gap I made a "donut" out of a sheet of aluminum. I used an air-shear, but tin snips should work too. I then screwed the fan to the aluminum with 8 screws. Then I bent the aluminum to fit the curves of the inside of the stock shroud. Then I used Pop-rivets around the circumference to hold the aluminum to the shroud. It turned out to be pretty solid.
FYI: For rivets that don't tighten down real well, you can place a hammer on the back side of the rivet and then hit the other side with another hammer. This will smash the rivet and make it tighten up on the metal. Stainless steel rivets will anchor down better than aluminum rivets, but they are much harder to use with a pop-rivet tool.
Then I sealed up the circumference with some silicone to make it more secure and air tight where the aluminum and the shroud meet.
Here it is all put back together.
I would certainly recommend this mod to anyone that can tackle it. I expect to get better MPG, a few more HP, and better cooling on hot days and in traffic. Oh, and the faster warm-up, and quieter engine is nice too.
I have made an upgrade to this mod. I added a switch to the fan so that I can turn the fan ON whenever I want and keep it on, which helps the A/C stay cold during traffic jams because of the extra air blowing through the condenser.
I recently added a 5.2" SPAL fan on the transmission cooler. I can control it separately from the engine coolant fan. I should only have to use it when off-roading or towing.