Skillet
Skillet
What is the 
level of replacing a fan clutch and updating the thermostat?
level of replacing a fan clutch and updating the thermostat?
Fan clutch solves overheating
- Thread starter landtank
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- Thread starter
- #202
Skillet said:What is the
1 maybe,
The fan assembly comes out with 4-12mm nuts and the the fan comes off the clutch with 4-10mm nuts.
The Thermostat change requires draining the coolant from the radiator and then removing 3-12mm nuts. The new Stat needs to be positioned so the jiggle valve is at the 12:00 position.
Maybe an hour worth of work, which 20 minutes is waiting for the coolant to drain.
I am having the same usual coolant/AC problems. I'm going to try to knock out the temp gauge mod this weekend, and I am tired of not having any AC. It works a little around town, but on the freeway--forget it.
As far as I can tell everything is working as far as t-stat and fan clutch. When the truck has overheated enough to shutoff the AC, the fan clutch only spins about 3 to 4 blades when I give it a good push.
I just don't think that the system can handle the southern Alabama heat that it has to deal with. In my opinion, the problem is probably a compilation of things. My '97 has 158k on it (though was rebuilt at 120k) and I think the whole system just slowly degrades. Replacing everything would probably fix it, but that isn't cost effective.
Anyhow, following this fan clutch stuff has left me confused and bewildered, but I am interested in adding an auxiliary fan.
My other though is that the trans cooler seems to be blocking a good chunk of the rad. Anyone though of repositioning it? I'm wondering if it could be repositioned Humvee style, flat with a louvre in the hood.
My other though was finding a small electric fan I could jam between the radiator and the trans cooler. Anyone know a good source for an electric fan? I'd rather avoid buying a new one. Anyone now a good OEM source I could find at a U-Pull?
As far as I can tell everything is working as far as t-stat and fan clutch. When the truck has overheated enough to shutoff the AC, the fan clutch only spins about 3 to 4 blades when I give it a good push.
I just don't think that the system can handle the southern Alabama heat that it has to deal with. In my opinion, the problem is probably a compilation of things. My '97 has 158k on it (though was rebuilt at 120k) and I think the whole system just slowly degrades. Replacing everything would probably fix it, but that isn't cost effective.
Anyhow, following this fan clutch stuff has left me confused and bewildered, but I am interested in adding an auxiliary fan.
My other though is that the trans cooler seems to be blocking a good chunk of the rad. Anyone though of repositioning it? I'm wondering if it could be repositioned Humvee style, flat with a louvre in the hood.
My other though was finding a small electric fan I could jam between the radiator and the trans cooler. Anyone know a good source for an electric fan? I'd rather avoid buying a new one. Anyone now a good OEM source I could find at a U-Pull?
- Thread starter
- #204
Pete, I think you might be getting ahead of yourself a little. Get the temp gauge modded, that way you can see what temps you're running and then start to diagnose.
A properly maintained stock cooling system should keep up with the heat demands of daily operation. If you need more airflow than what is there then you need to find the problem, adding electric fans is a band-aid.
A properly maintained stock cooling system should keep up with the heat demands of daily operation. If you need more airflow than what is there then you need to find the problem, adding electric fans is a band-aid.
landtank "Todays drive home from The cape was absolutely perfect as far as truck temps are considered.
The ambient temp was 90* and the truck performed great.
Most of the drive the needle was at normal and would only rise slightly on pulling a grade with the TC unlocked. On those occasions where a downshift was needed the needle actually dropped some and the previous situation where I had a temp spike from the upshift at the top of the climb has dissappeared.
As I just tweeked the control plate last time I don't actually know where it is but will post that in a new thread outlining the complete proceedure of what I've done.
At this point I've gone as far aas I can on my own and will need data from other's to refine this for a better across the board ajustment for multiple trucks."
Great to hear! Any idea where I can get the parts local for the temp guage mod? I would be happy to help you get more data on the fan clutch.
BTW, the squeal has come back.....
The ambient temp was 90* and the truck performed great.
Most of the drive the needle was at normal and would only rise slightly on pulling a grade with the TC unlocked. On those occasions where a downshift was needed the needle actually dropped some and the previous situation where I had a temp spike from the upshift at the top of the climb has dissappeared.
As I just tweeked the control plate last time I don't actually know where it is but will post that in a new thread outlining the complete proceedure of what I've done.
At this point I've gone as far aas I can on my own and will need data from other's to refine this for a better across the board ajustment for multiple trucks."
Great to hear! Any idea where I can get the parts local for the temp guage mod? I would be happy to help you get more data on the fan clutch.
BTW, the squeal has come back.....
- Thread starter
- #206
Cattledog said:
only place locally that you might have a shot at that I know of would be You-Do-it electronics in Needham MA.
Did you service the e-brake yet?
landtank said:
Pete,
Landtank is correct on all of these points; especially his comment that a properly running stock cooling system will keep up with the cooling demands in Alabama.
Data point:
Area: New Mexico and Arizona deserts and mountains
Temps 95*+ (2 weeks ago) Blazing hot sun most of the trip there and back.
Distance: 8 hrs each way at 70 MPH (~400 miles 50% interstate 45% secondary 5% dirt)
Vehicle: 6 adults (161k miles, lifted, armored, MT's, etc.) with accurate aftermarket coolant temp gauge + stock gauge.
A/C on high recirc most of the time. No complaints from 3rd row passengers most of the time.
The truck has the original '97 radiator & hoses, with fresh belts & thermostat, and a 1yo blue hub Toyota fan clutch.
I tracked the temps and carefully watched the gauge there and back; 8 hrs each way. Coolant temp was never an issue and not much higher than seen on 50* days. Of course, the stock gauge never moved from the "normal" indication.
Gauge temps ranged between 194* and 212* depending on grade and the distance up the grade.
You say it's not justifiable to replace the parts needed to get the cooling system up to speed but I would disagree. In fact, it does not make sense *not* to replace those parts and get your truck's cooling system working properly.
-B-
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That's the thing. The entire block was rebuilt 40k ago. PHH blew pulling a heavy Uhaul over a pass in TN with both heaters on 20k ago. New HG (second one) 10k ago. My fan clutch seems to work in that it spins when it should, but I guess it must not be spinning as fast as it should.
Can I adjust the non-blue OEM clutch? Do I need to buy a new one and then mod it? Different oil?
I've got to move to KY/TN in a month and the last thing I need is my truck overheating out there again. That and I'm losing the hearing in my left ear driving on the freeway with the windows down all the time
Can I adjust the non-blue OEM clutch? Do I need to buy a new one and then mod it? Different oil?
I've got to move to KY/TN in a month and the last thing I need is my truck overheating out there again. That and I'm losing the hearing in my left ear driving on the freeway with the windows down all the time
- Thread starter
- #209
For those of you that have gotten my adjustment pdf, my clutch is adjusted to a target temp of 95*.
I realise this is quite a drop from where I started but I'm not going to fight it.
For the rest, I'll get something up here ASAP.
here is a pic of my truck and camper that was used as a test bed.
I realise this is quite a drop from where I started but I'm not going to fight it.
For the rest, I'll get something up here ASAP.
here is a pic of my truck and camper that was used as a test bed.
Hey Rick,
You also may want to point out that you rig is FULLY armored, supersized power steering cooler, running 35's with 4.88's and has a winch out front. That equipment adds alot of extra mass to pull around.
You also may want to point out that you rig is FULLY armored, supersized power steering cooler, running 35's with 4.88's and has a winch out front. That equipment adds alot of extra mass to pull around.
- Thread starter
- #211
Cattledog said:
Yes, but the beauty of this clutch is that it's variable, it only turns on for what the engine needs. So if you have a lighter setup or in cooler weather the clutch simply doesn't come on as strong, this adjustment should work for everyone and have no negative impact on MPG for any given load or ambient temp.
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Pete483 said:That's the thing. The entire block was rebuilt 40k ago. PHH blew pulling a heavy Uhaul over a pass in TN with both heaters on 20k ago. New HG (second one) 10k ago. My fan clutch seems to work in that it spins when it should, but I guess it must not be spinning as fast as it should.
Can I adjust the non-blue OEM clutch? Do I need to buy a new one and then mod it? Different oil?
I've got to move to KY/TN in a month and the last thing I need is my truck overheating out there again. That and I'm losing the hearing in my left ear driving on the freeway with the windows down all the time
With the older clutch there is no adjustment, the only upgrade option is changing the fluid. If it's not leaking and the bearing is good, check by feeling for play in the fan, then the fluid can be upgraded. I have had good success putting 6000 and 10000 cst in the earlier style clutches on trucks and 4runners.
semlin
curmudgeon
ok here is my data point
-the 110 adjustment mod did very little. the old fan clutch still outperforms the new one significantly. ambient temps were low 90s today. the truck ran roughly 4-5 degrees hotter with the blue clutch and worse with AC on. It noticeably heated up on even short grades, took longer to cool than the old clutch afterwards, heated up more at idle and actually climbed in temp on the flat highway when I exceeded 60 mph with the ac on. max temps seen were about 208-209 but I was turning off the AC to avoid 210. it was at 207 at one point on the level highway with the AC on.
from this I think that I did not tweak it enough to fully engage the fan clutch before 210 plus I think that the partial engagement is pretty ineffective at cooling the truck. this fan clutch is almost new and did not look like it had leaked.
Rick can you comment on the levels of oil you had in yours before and after filling compared to my note earlier? I am thinking that even if I were to clock it back to 95 as you did, I would also want to see the partial engagement be more effective which to me means more oil.
At this stage I don't have time to tweak it before my trip so I am going to tow the boat with the old fan clutch.
-the 110 adjustment mod did very little. the old fan clutch still outperforms the new one significantly. ambient temps were low 90s today. the truck ran roughly 4-5 degrees hotter with the blue clutch and worse with AC on. It noticeably heated up on even short grades, took longer to cool than the old clutch afterwards, heated up more at idle and actually climbed in temp on the flat highway when I exceeded 60 mph with the ac on. max temps seen were about 208-209 but I was turning off the AC to avoid 210. it was at 207 at one point on the level highway with the AC on.
from this I think that I did not tweak it enough to fully engage the fan clutch before 210 plus I think that the partial engagement is pretty ineffective at cooling the truck. this fan clutch is almost new and did not look like it had leaked.
Rick can you comment on the levels of oil you had in yours before and after filling compared to my note earlier? I am thinking that even if I were to clock it back to 95 as you did, I would also want to see the partial engagement be more effective which to me means more oil.
At this stage I don't have time to tweak it before my trip so I am going to tow the boat with the old fan clutch.
- Thread starter
- #214
In the thread outlining my mod proceedure there is a pic of the hub side that shows the oil level I had before I added some. It was basically level with the top of that bowl area in the casting, if that makes sense.
Ive got the same problems as mention from others about the overheating. What exactly do I do to my new Toyota fan clutch?? I've changed all other cooling items and my mechanics ya mechanics 4 of them have given up after Ive spent over $2,000 and 2 years trying to find out why my truck runs hot to the red pulling a small trailer of in traffic jams.
93Fj80
Thanks
Rod
93Fj80
Thanks
Rod
- Thread starter
- #216
The proceedure for how I changed the fan clutch can be found here Clutch mod Currently I'm running the OFNA oil but will be replacing it with the Toyota 6K oil. That oil can be gotten from CruiserDan here on the board
landtank said:
LBComments: I don't agree Rick it can very well affect mileage, and may be why we in the US have such a light fluid.
HBComments: A viscous clutch is not a coupling, so by definition it never is disengaged fully, nor is it ever engaged fully. It turns on from the heat in the thermostat, which is the sum of engine/bay/ambient temps. As such, as ambient temp increases, so does fan load. And the engine could exactly not need the fan engaged when it actually is.
I would expect a healthy increase in mileage from a on/off mechanical fan or electrics, either driven from engine temp sensors, not radiator/engine bay/ambient temps. The 4R guys have already found this out on some of the other forums.
My .02
Scott Justusson
When you refer to the "earlier style clutches", do you mean the same Toyota p/n that came from the factory on FZJ80s?
I added some 10,000 cst OFNA brand hobby store silicone to mine this evening. The factory fill appeared to be at least as viscous as the fresh silicone fill, if not slightly more so. After initial qualitative testing, the additional fluid does not appear to have a material affect on the clutch's ability to pull air, so I think I will have to purchase an internal thermostat "blue hub" clutch from CDan, as I could not ascertain a method to adjust the factory original.
Has anyone here rejuvenated and/or adjusted their original style FZJ80 clutch?
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Rod,
It seems to be a rather simple matter to adjust it yourself. It only took about 7 minutes to remove the clutch and the same amount of time to reinstall it. Separating the clutch halves only took a couple of minutes with the deliberate application of a chisel. I don't have the new blue hub clutch, but it seems to me that LandTank's temperature calibration process is the simplest part of an already easy process.
I'd wager that it's not much more difficult than changing the engine oil and filter, and therefore not worth the trouble of shipping it both ways. CDan and Hobbytown.com have the 10,000 cst silicone oil in stock.
Jon
