FJ80 fan clutch and electric fan questions (1 Viewer)

Joined
Aug 19, 2022
Messages
9
Location
Idaho
Hi
I just had the AC fixed on my FJ80 and the AC shop is telling me my fan clutch is bad. I had just installed a new one 2 days per them telling me the original was also bad.
Their input was it was not pulling air when the engine was warm. I checked it after driving it home 20 miles at 100 degrees heat. It seemed to be pulling air and engine temp was normal. I comparted the old fan clutch resistance with the replacement and really can not tell much difference (warm or cold). I've had overheating issue when pulling an extended grade while off roading (3300 ft in 8 miles for example).
So, contemplating adding an electric fan and the possibly getting a higher volume fan clutch (does that exist?).
If you have installed an electric fan, who did you get it from {make and model please). Ditto for the fan clutch.
Words of wisdom please from peeps who have fought this battle with a 91 FJ80.
 
Joined
Sep 10, 2013
Messages
1
Location
Portland, OR
Second that. I used this stuff: Amazon product. I took about 15ml out of the clutch with a syringe and replaced with 15ml of this thicker stuff. Seems to be about perfect for PNW weather, but I'd probably add more if I lived somewhere where it gets really hot (and doesn't get cold -- this will cost you a bit when you go to use your heater in the winter).
 
Joined
Aug 19, 2022
Messages
9
Location
Idaho
Second that. I used this stuff: Amazon product. I took about 15ml out of the clutch with a syringe and replaced with 15ml of this thicker stuff. Seems to be about perfect for PNW weather, but I'd probably add more if I lived somewhere where it gets really hot (and doesn't get cold -- this will cost you a bit when you go to use your heater in the winter).

Cool. THIS is helpful.
 
Joined
Jul 26, 2020
Messages
642
Location
Juneau, Alaska
OK

That is not really helpful. What kind of oil?
The simple post may have been vague, but I imagine he was giving a nod to search the topic on here - plenty of good write ups on the exact procedure that will make it an easy job. The search function on the forum isn’t always great, but google works well if you add “ih8mud” to your key words
 
Joined
Aug 19, 2022
Messages
9
Location
Idaho
The simple post may have been vague, but I imagine he was giving a nod to search the topic on here - plenty of good write ups on the exact procedure that will make it an easy job. The search function on the forum isn’t always great, but google works well if you add “ih8mud” to your key words
thank you!
 
Joined
Oct 5, 2022
Messages
2
Location
NorCal
Had the same issue with my stock fan clutch not engaging when high temp is present. replaced it with a heavy duty cycle from rock auto (us motor works part# 22074) and wala. funny because I remember most older cruisers when starting you can here the fan fully engaged, then calm down after a 20/30 sec. also it was causing an issue with the ac condenser not pulling enough air through it not cooling properly ect.

I found out there are different types of clutches you can use depending on what duty cycle you are after. I believe heavy duty comes on 70% or more of the time where as light duty stays around 30 to 40%? correct me if I'm wrong.
 
Joined
Jan 5, 2017
Messages
4,070
Location
Charlotte, NC & Alexandria, VA
Hi
I just had the AC fixed on my FJ80 and the AC shop is telling me my fan clutch is bad. I had just installed a new one 2 days per them telling me the original was also bad.
Their input was it was not pulling air when the engine was warm. I checked it after driving it home 20 miles at 100 degrees heat. It seemed to be pulling air and engine temp was normal. I comparted the old fan clutch resistance with the replacement and really can not tell much difference (warm or cold). I've had overheating issue when pulling an extended grade while off roading (3300 ft in 8 miles for example).
So, contemplating adding an electric fan and the possibly getting a higher volume fan clutch (does that exist?).
If you have installed an electric fan, who did you get it from {make and model please). Ditto for the fan clutch.
Words of wisdom please from peeps who have fought this battle with a 91 FJ80.
Ever solve your problem?

IIRC, the FJ80s& FZJ80s (US domestic models) had white hub fan clutches and the replacements are blue hub (light vs. medium duty, black hub being heavy duty). I just replaced the OEM white hub clutch on my son's '95 with a new OEM blue hub. It made absolutely no measurable difference.

I have the white hub on the bench; I'm going to drain it and refill with 15k cSt oil and see if that makes any measurable difference.
 
Joined
Aug 22, 2017
Messages
2,365
Location
Los Angeles
IIRC, the blue fan clutch and others will not work on the FJ80 w/ 3F-E motor. Go with the Aisin (OEM) hub (green hub), and drain and fill with 15k or desired thickness oil from any hobby store. If adding thicker oil is not enough, you can also adjust timing on the clutch to open fully at certain temperature. - There are writeups for that as well. I would avoid converting to electric fans....
These mechanical fan pulls ton of air, especially for the 3FE that produces alot of heat vs hp....
 
Joined
Aug 19, 2022
Messages
9
Location
Idaho
Update

I added a 12" high volume high quality electric fan in front of the AC coils. Shop seemed impressed with what I did. I added a switch to the dash to turn it on and off with a relay (it pulls up to 17 amps).
 
Joined
Dec 8, 2006
Messages
10,978
Location
New Jersey
Website
www.sdsysdesign.com
Update

I added a 12" high volume high quality electric fan in front of the AC coils. Shop seemed impressed with what I did. I added a switch to the dash to turn it on and off with a relay (it pulls up to 17 amps).
That sounds like you are masking an underlying cooling system problem. The OEM AISIN fan clutch FCT-049 with the green hub is very robust out of the box, and the 3FE puts out a whole 155 bone crushing horses. The OEM cooling system should have no trouble keeping things cool, assuming things are working correctly.
Is your fan shroud intact and in place? Without a proper fan shroud it will not cool well.
 
Joined
Aug 19, 2022
Messages
9
Location
Idaho
That sounds like you are masking an underlying cooling system problem. The OEM AISIN fan clutch FCT-049 with the green hub is very robust out of the box, and the 3FE puts out a whole 155 bone crushing horses. The OEM cooling system should have no trouble keeping things cool, assuming things are working correctly.
Is your fan shroud intact and in place? Without a proper fan shroud it will not cool well.
Yup. Actually had to install one. The guy who did the top end before I bought it left it off. I'm not convinced the fan clutch was ever bad, but did buy a new one from Cruiser Outfitters. It pulls air when I checked it on a 100 degree day. My only issues have been off road pulling a grade. Not sure about the radiator. It looks aftermarket. Installing the electric fan was reasonably easy and fun. I like the extra margin at my fingertips.
 
Joined
Aug 22, 2017
Messages
2,365
Location
Los Angeles
That sounds like you are masking an underlying cooling system problem. The OEM AISIN fan clutch FCT-049 with the green hub is very robust out of the box, and the 3FE puts out a whole 155 bone crushing horses. The OEM cooling system should have no trouble keeping things cool, assuming things are working correctly.
Is your fan shroud intact and in place? Without a proper fan shroud it will not cool well.
In my experience, the OEM cooling is good for stock rigs with stock tires and no additional weight, etc. In other words, mall crawlers, soccer mom duty, running errands.
Once you add in extra weights, larger tires, etc. The stock cooling is marginal at best given all components are in working order. Rememeber, the bone crushing 155 hp produces alot of heat when you are pushing the rig at a high rpm to compensate for the lack of HP....Aisin Green hub with thicker oil will do the trick....2 core alum. radiator will work much better than copper/brass units for non pavement operations. Ask me how i know...
 
Joined
Aug 19, 2022
Messages
9
Location
Idaho
In my experience, the OEM cooling is good for stock rigs with stock tires and no additional weight, etc. In other words, mall crawlers, soccer mom duty, running errands.
Once you add in extra weights, larger tires, etc. The stock cooling is marginal at best given all components are in working order. Rememeber, the bone crushing 155 hp produces alot of heat when you are pushing the rig at a high rpm to compensate for the lack of HP....Aisin Green hub with thicker oil will do the trick....2 core alum. radiator will work much better than copper/brass units for non pavement operations. Ask me how i know...
Not sure I would use the word 'bone crushing' to describe the stock engine. LOL
 
Joined
Dec 8, 2006
Messages
10,978
Location
New Jersey
Website
www.sdsysdesign.com
In my experience, the OEM cooling is good for stock rigs with stock tires and no additional weight, etc. In other words, mall crawlers, soccer mom duty, running errands.
Once you add in extra weights, larger tires, etc. The stock cooling is marginal at best given all components are in working order. Rememeber, the bone crushing 155 hp produces alot of heat when you are pushing the rig at a high rpm to compensate for the lack of HP....Aisin Green hub with thicker oil will do the trick....2 core alum. radiator will work much better than copper/brass units for non pavement operations. Ask me how i know...
The only time my 3FE ran hot it was due to an old fan clutch. In 25 years of daily use including 2 cross country trips pulling a trailer it happened once. And I wouldn't consider my 91 a "mall crawler".
 
Joined
Jan 30, 2012
Messages
533
Location
Orange County California
I have been having (kinda) the same issue with my 3FE. It runs HOT while on the Highway with the A/C on and while driving up grades. I have replaced pretty much everything but i got the same issue. Radiator, Fan Clutch, Thermostat, Water pump, all hoses, pressure tested and flushed numerous times.
 
Joined
Aug 19, 2022
Messages
9
Location
Idaho
I have been having (kinda) the same issue with my 3FE. It runs HOT while on the Highway with the A/C on and while driving up grades. I have replaced pretty much everything but i got the same issue. Radiator, Fan Clutch, Thermostat, Water pump, all hoses, pressure tested and flushed numerous times.
The electric fan was actually pretty easy and fun to install, including putting in a switch in the dash board. You might consider just biting the bullet and adding it.
 

Users who are viewing this thread

Top Bottom