97 Fan Clutch replacement - super simple

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May 3, 2010
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Tucson
A local shop (mis)diagnosed my cooling problem as needing a new fan clutch. Bid 3.3 hours for the job. Called the dealer, they wanted 2.7 hours. Couldn't see what the big deal was so I decided to take on myself.

The super handy guys on this site will probably laugh at such a trivial job but for all those other "just handy enough to really screw it up guys" out there - this is 8 nuts, 2 bolts and less than an hour. Do it yourself.

Biggest trick is breaking the four nuts loose without just turning the water pump. I used two 12mm closed end wrenches and while I held one I tapped on the other wrench to break each nut free. With four nuts off I took the two top bolts off the fan shroud that hold it to the radiator. By leaning the shroud away from the radiator there is room to slip the fan and clutch assy out. Four more nuts to remove the fan from the clutch. Replaced with Toyota part. Saved $300.
 
Joined
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Tucson
Who knew?

I didn't know anybetter? Spent several hours last night reading all of viscous clutch mods on this site. The $400+ bid on the fan clutch inspired me to pick up my wrenches again. Did the fan clutch, PCV valve, both ventilation hoses and a new heater control valve. When I ran up against the factory heater hose clamps that weren't obvious how to undo (turns out they are just a variation on how a SPAM can opens) I googled and found this site.

My original problem was A/C cutting off (Temperature control swith shutting it off) First visit was a pound of refrigerant which I told them didn't make sense but they said it was fixed. Second visit Fan Clutch, which I did my self. (Their diagnosis was based on placing a huge fan in front of the radiator and my air coming back on - so that lends merit to all of the viscous clutch mods to make the fan turn faster). Third Visit they did a thermostat, then a water pump inspection, and finally had the radiator rodded out which was the root cause. Truck now runs much cooler, AC works better than ever. Shop said temp gage barely moves from 180 to 220. Turns out that fact and a fix are well documented on this site as well.

My new fan clutch does have a blue hub vs. the old black one. Is there a known issue with this or is replacing the fluid just a performance upgrade?

With my new found confidence to do my own work I took on the antenna motor/mast, and fixed the tailgate latch. Next up OEM shock absorbers that just arrived, then rear window motor if I can find a used one.
 
Joined
Jul 20, 2004
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24,774
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Chandler, AZ
...
My new fan clutch does have a blue hub vs. the old black one. Is there a known issue with this or is replacing the fluid just a performance upgrade?
...

To get good A/C performance in AZ, good airflow is needed. The blue hub clutches have proven to be weak, even when new, causing A/C vent temps to rise, especially at idle. If your original clutch is a black hub Aisin, I would consider changing the fluid in it and running it, they are the strongest available.

For the best AZ performance, leave the valve alone and step up fluid viscosity, most here are running 10K+ in the early clutches and 20K+ in the late blue hubs with good results. I have fluid if you can make it to PHX, or check out the local forum, some in Tucson have done clutch mods.

AZ- Copper State Cruisers
 
Joined
Jan 16, 2007
Messages
660
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Austin, TX
Tools is right, the black hub is far superior, I hope you didn't let it get away. Weak fan clutches are the #1 killer of compressors. You have to have good air flow to cool down the refrigerant while it's in the condenser. I'd clean the condenser to maximize heat dissipation, which ultimately lowers vent temps. Do not use a pressure washer, you will bend the fins. You can use an acid safe for aluminum or any degreaser, such as simple green.
 
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Joined
Jan 5, 2010
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Vermont
so the blue is weaker? I just ordered one.

I have an Eaton and replaced the silicone with a heavier weight. No roar, no noticeable temp differences and going uphill temp spikes remain. Mind you I've serviced/replaced the cooling system except for a rad replacement which isn't needed. I've read endless posts on this s*** w/o coming across the idea that the blue clutch is inferior. In fact quite the contrary, seems to be the clutch of choice around here.

Of course, now that its in transit to my door, I find out its inferior.
 
Joined
Jan 16, 2007
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Austin, TX
I wouldn't worry about it too much, skii. You'll have a better clutch and finding a black hub might have proven to be difficult.

The green hub is better than the black, but there might be a fitment issue as the snout is shorter, which may cause the fan to hit the shroud. The green hub is used on the 3FE, which is far superior to the 1FZ.
 

Romer

fatherofdaughterofromer
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Sep 14, 2003
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11,567
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Centennial, Colorado
I have been running a blue fan cluth for 3 years with thicker fluid ~8000K with a supercharger, dual batts and have had no issues. I had not heard they were inferior. The Blue one will be fine for you.


A new Radiator makes a big difference. I replaced mine with a new 94 Toyota 80 series Rad because I think the design is superior and it was about $300 cheaper than a 97. Plus it bolts right in.
 
Joined
May 3, 2010
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Tucson
If it ain't broke keep trying?

Thanks for all the great info! Get to Phoenix a lot (lived in Gilbert for 10 years) so I may take you up on the fluid offer Tools. Black Hub is in the trash but maybe hasn't gone to the curb yet. But it was diagnosed as leaking and needing to be replaced even before it was believed to be the cause of the AC. Would you still refill it?

With the new clutch and thermostat, my truck was still running 210-220 with air temps in the 80s. After radiator was rodded out runs 185-195 when the shopped check temp in different situations. This is visible even with lousy temp gage (needle has negative slope). It has never run with needle pointing down since I owned it.

I got sold a rebuilt radiator 7 years ago when I lost belts and the original blew up. My truck has probably been running too hot ever since but I never realized it with the temp gage only moving two needle widths over 40 degrees. A/C would cut off anytime I towed something up hill.

I am thinking I will hook up the boat on a 100+ day and see what happens. If it stays cool going uphill I won't mess with it. If it heats up again I will tackle new clutch fluid and maybe a new radiator.

I will also try some simple green on the A/C heat exchanger - can't hurt. Thanks.
 
Joined
Jan 16, 2007
Messages
660
Location
Austin, TX
Just a bit late on the reply, Fido had to go outside.... Romer makes another good point. The Koyo rads are the best replacement if you have a OEM plastic/aluminum radiator.

Everything can be deduced to heat dissipation. Air flow and fluid circulation is very critical.

For those of you who have been left behind, condensers are in front of the radiator. Sometimes tranny and oil coolers are in front of them. If they have insects, dirt, and grime restricting the air flow, things aren't going to work as we'd like.

Clean them and watch temps, both at the vents and on the dash, fall.
 
Joined
Jul 20, 2004
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Chandler, AZ
With the proper fluid, a blue hub will work, a bunch are running with success. IMHO the early blue and black are superior, they have greater torque transfer and idle performance.

Check your coolers for bug entrails. I prefer water and time to clean, run a sprinkler on it for and hour or so and rinse.
 

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