Aisin FCT-049 fan clutch (2 Viewers)
- Thread starter Godwin
- Start date
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Gretsch
SILVER Star
So if it did, would that indicate an issue with its operation? It seems to make sense that having it lock up at highway speeds wouldn't do much with the rush of air you would already be getting from travelling that fast. I seem to recall several situations however where mine would lock up while driving highway speeds. Could hear the roar for a bit while on the highway and watched my temp gauge drop down some as a result. I have the normal 2F clutch and not the one the thread is discussing. But curious now if it shouldn't be locking up with the motor turning 3K RPM. It made a noticeable difference on the temp gauge if memory serves so seemed to help with cooling mine at that speed. Likely didn't help with gas mileage though.
Ok, here’s going way out on a limb in theoryland:
When the fan clutch does engage at highway speeds (usually for a moment then disengages when it spins out the oil) I can definitely feel the drag on the engine when it does.
If the fan clutch was always engaged at highway speed, it would put a significant load on the engine which would need to be compensated naturally by pressing down on the gas pedal farther to maintain a certain speed.
So more gasoline would be required to maintain a desired speed, and more gasoline = more heat generated.
It could be …(out in theoryland) that having a fan clutch locked up at highway speeds actually could cause the engine to run even hotter -,because the gas pedal is being pushed down farther.
Dunno - just a funny thought that came to mind.
When the fan clutch does engage at highway speeds (usually for a moment then disengages when it spins out the oil) I can definitely feel the drag on the engine when it does.
If the fan clutch was always engaged at highway speed, it would put a significant load on the engine which would need to be compensated naturally by pressing down on the gas pedal farther to maintain a certain speed.
So more gasoline would be required to maintain a desired speed, and more gasoline = more heat generated.
It could be …(out in theoryland) that having a fan clutch locked up at highway speeds actually could cause the engine to run even hotter -,because the gas pedal is being pushed down farther.
Dunno - just a funny thought that came to mind.
John McVicker
SILVER Star
Also, my FCT 049 has come on at hiway speed. Not often & not for long and then it shuts off. When it has come on I can of course hear it AND see the temp immediately drop down.
As I try to remember the exact circumstances when this happens…I think it has mostly happened in high ambient temps & climbing 3-5 mile hills on freeway…but at much slower speeds, maybe 40-45 mph with the pedal floored as I slowly go up the hill.
As I try to remember the exact circumstances when this happens…I think it has mostly happened in high ambient temps & climbing 3-5 mile hills on freeway…but at much slower speeds, maybe 40-45 mph with the pedal floored as I slowly go up the hill.
When the ambient temp rises above a mechanical Fan Clutch's set point for engagement, it will lock up, regardless if the truck is moving 60 mph or 0 mph. It's not necessary for the FC to engage at highway speeds, but that's just something inherent with the design.
Depending on the FC design and viscosity of the fluid it's filled with, there will be a gray area around that set point where the clutch will partially engage.
Depending on the FC design and viscosity of the fluid it's filled with, there will be a gray area around that set point where the clutch will partially engage.
Regarding the 210* number - the stock 190* thermostat doesn’t reach full open until 212*. So any change to the system to engage the fan at a temp lower than 212* would essentially have the cooling system working against itself.
This weekend I drove 275 miles from Phoenix to Flagstaff and back, which is an elevation gain of more than 5500 feet. July in AZ is hot, saw 230* quite a bit on those long inclines (w heater on), and the fan clutch was definitely locked up then, regardless of speed. The rest of the time, temps varied between 200-210 mostly (w ac on), no FC lockup at those points, as expected
This weekend I drove 275 miles from Phoenix to Flagstaff and back, which is an elevation gain of more than 5500 feet. July in AZ is hot, saw 230* quite a bit on those long inclines (w heater on), and the fan clutch was definitely locked up then, regardless of speed. The rest of the time, temps varied between 200-210 mostly (w ac on), no FC lockup at those points, as expected
This would be my expectation in a higher ambient temperature, especially with a tow load. Unless I'm missing something, I would assume your cooling system is working exactly as it should - thermostat fully open approx 212 and the rest of the system maintaining the water temp there.
Although in this thread you haven't confirmed what thermostat you have installed.
reddog90
SILVER Star
I only have a few miles with my new WP and unaltered FCT-049 clutch. But I have immediately noticed more power driving around the neighborhood and a few miles on the freeway to work. I never noticed a change in sound with the red base clutch, and I notice the new green base clutch cycling on and off. This makes me think my old red one was locked on and constantly stealing some power. This may be confirmation bias after reading OSS's post earlier but I'm not sure what else to make of this. I spun the old water pump by hand after removing it and it doesn't feel like it was dragging. I have a digital water temp gauge and my temps don't seem any different than before.
I noticed with 111* temps that my FCT049 seems a little bit overwhelmed. This was yesterday in Austin.
Temps were climbing to about 210* at cruise of 75mph up and down hills. When I parked, it was heat soaked really bad and the engine bay was the hottest I’ve ever seen. I could have slowed down and the temps at cruise would have gotten better.
Aside from running warm the truck was comfy with ac going full blast at speed for 3 hours and didn’t actually do anything wrong. I run an aux digital temp gauge and I was watching temps closely.
I’m going to buy another fan clutch and try adjustment and fluid swaps at a later date. I think that I’ve just established what I’m comfortable with and nothing more.
Temps were climbing to about 210* at cruise of 75mph up and down hills. When I parked, it was heat soaked really bad and the engine bay was the hottest I’ve ever seen. I could have slowed down and the temps at cruise would have gotten better.
Aside from running warm the truck was comfy with ac going full blast at speed for 3 hours and didn’t actually do anything wrong. I run an aux digital temp gauge and I was watching temps closely.
I’m going to buy another fan clutch and try adjustment and fluid swaps at a later date. I think that I’ve just established what I’m comfortable with and nothing more.
In Los Angeles (summer) this is why I really really want to put louvered vents in the hood. Particularly being fully and functionally smogged.
I've bought some louvers LINK but yet to install...
I saw these installed on another MUD members truck (pix on MUD), and they seemed to fit very nicely without having to cut any of the hood ribs.
I've bought some louvers LINK but yet to install...
I saw these installed on another MUD members truck (pix on MUD), and they seemed to fit very nicely without having to cut any of the hood ribs.
John McVicker
SILVER Star
I completely agree that they would help. I’ve seen cold rain hit the hood and instantly steam off. I couldn’t even touch the hood prop yesterday.In Los Angeles (summer) this is why I really really want to put louvered vents in the hood. Particularly being fully and functionally smogged.
I've bought some louvers LINK but yet to install...
I’m sure the bumper and winch are hampering air flow, but if I could let it all vent out the top it would help a ton.
Every piece of plastic or rubber on the drivers side of my truck is cooked. I’m killing vacuum caps yearly. It already cooked my compressor once.
Every piece of plastic or rubber on the drivers side of my truck is cooked. I’m killing vacuum caps yearly. It already cooked my compressor once.
If you have a safe place to do so (garage or carport), you can open the hood after you park the truck for the day, and let all that heat out, rather than having it sit there cooking everything.
If you have a safe place to do so (garage or carport), you can open the hood after you park the truck for the day, and let all that heat out, rather than having it sit there cooking everything.
I drive it too much. The hood would never go down.
I already pride myself on this staying a very turn key normal truck, I think that the fan clutch mods will take it to the next level.
When it was running warmer than normal I had been keeping up with an 80 series over rolling hills from 70-85 mph for easily 45 mins. I never passed him, but he never lost me.
Maximum race tractor.
I already pride myself on this staying a very turn key normal truck, I think that the fan clutch mods will take it to the next level.
When it was running warmer than normal I had been keeping up with an 80 series over rolling hills from 70-85 mph for easily 45 mins. I never passed him, but he never lost me.
Maximum race tractor.
John McVicker
SILVER Star
Negative. Now that it’s gonna be cool here in texas I’ve shifted priorities elsewhere for a few months.
Redline landcruisers sells a modified 3FE fan clutch ready to go if you want to take their word for it.
Redline landcruisers sells a modified 3FE fan clutch ready to go if you want to take their word for it.
It's that time of year again.
@Godwin @HemiAlex @John McVicker do any of you have update on the fan clutch oil mod? I'm ordering some 20000CST oil today. I have the original fan clutch (red hub FCT-017) in storage and figured I'd open it up and mod it, then swap it in place of the FCT-049 I've had installed for a few years.
EDIT: opened up the FCT-017 tonight, and it is not built like the FCT-049... there are no adjustment screws. The oil ports are quite a bit smaller than the -049. I just closed it up. I'll mod the 049 that is installed in the truck when the oil arrives.
@Godwin @HemiAlex @John McVicker do any of you have update on the fan clutch oil mod? I'm ordering some 20000CST oil today. I have the original fan clutch (red hub FCT-017) in storage and figured I'd open it up and mod it, then swap it in place of the FCT-049 I've had installed for a few years.
EDIT: opened up the FCT-017 tonight, and it is not built like the FCT-049... there are no adjustment screws. The oil ports are quite a bit smaller than the -049. I just closed it up. I'll mod the 049 that is installed in the truck when the oil arrives.
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John McVicker
SILVER Star
So I did a little extra reading on this today. Found a fairly decent explanation of the screw "settings" on this page:
Seems Godwin was on the right path to tuning the FC to lock up earlier than the stock setting.
Based on this info from the above link...
I took a closer look at Godwin's photos from the first page.
Initial "stock" setting, we can see that the valve would be closed over the outer hole in the rings (the 0 position from the above graphic)
When he moved the screws to the right, it appears the valve would be partially open especially at the outer hole located at the rings, akin to the A position from the graphic. I would assume this would allow for an earlier lockup given the same oil weight.
Tuning and Understanding your Toyota Viscous Fan Clutch
Landcruiser or Hilux overheating? Your factory fan clutch is probably under-filled and incorrectly set from factory. Fix this first and you may save a lot of time chasing issues. (4 Runner or Tacom…
neuralfibre.com
Seems Godwin was on the right path to tuning the FC to lock up earlier than the stock setting.
Based on this info from the above link...
I took a closer look at Godwin's photos from the first page.
Initial "stock" setting, we can see that the valve would be closed over the outer hole in the rings (the 0 position from the above graphic)
When he moved the screws to the right, it appears the valve would be partially open especially at the outer hole located at the rings, akin to the A position from the graphic. I would assume this would allow for an earlier lockup given the same oil weight.
