The Fan Clutch (clutch fan / fluid coupling) Thread

[rgsjue]

Replaced radiator and now gets hot when idling too long or low speeds, have not done thermostat. Fan clutch comes on but not till things seem to be too hot? Any ideas as to next move? Randy

[timsrv]

Hello and welcome to TVT! IMO replacing the thermostat should be your next move. They can and do get stuck (I've seen it many times). If it's stuck in a closed or partially closed position, it could certainly explain your problem. OEM thermostats are a bit unique on these vans. There are aftermarket ones listed, but some of them don't fit quite right and/or the travel of the valve is incorrect. For this reason I highly recommend a genuine Toyota thermostat. It's Toyota Part #90916-03046. You will also need the rubber seal that holds it in place. The seal is Toyota part #16325-63011.

I suspect your problem may actually be the fan clutch, but the T-stat is cheap and pretty easy to do (just consider it routine maintenance). Llamavan has a good write-up HERE (https://www.toyotavantech.com/forum/showthread.php?21-Replacing-your-van-s-thermostat) that explains how to replace it. The fact that your fan clutch engages is encouraging, but it needs to engage BEFORE the van overheats. Typically a good working fan clutch will engage when the temp needle hits the center or just slightly higher (about 200°F), and should stay engaged until temp comes down to 190° - 195°F (needle somewhere under half way). If yours isn't coming on until there's an overheat condition (needle around 3/4 or about 220° - 230° F), then it's got a problem.

If this is the case you have 2 choices. You can go get a new clutch (again I strongly recommend genuine Aisin/Toyota), or you could try to adjust the one you have. If you attempt to adjust, keep in mind this is not much more than a "hail Mary" and could quite possibly be a waste of time or even make the problem worse. Still, if you are financially challenged (like most of us these days) it could be worth a shot. If you attempt this, the 1st thing you need to do is remove the fan unit and separate the clutch from the fan. When you get to this point, the next step is opening the case. Keep in mind that this is a sealed unit and has a specific amount of silicone goo inside, so keep it laying flat and try not to damage the rubber seal or introduce dirt/foreign material into the clutch. Once open you will have access to the adjustment screws inside. See picture below:

http://i8.photobucket.com/albums/a23/timsrv/OpenedUp-1.jpg

To make the clutch engage at a lower temp, you will need to loosen these screws and turn the plate counter clockwise. How far to turn is somewhat of a guessing game, but I would think a movement of about 1/8" or so would be a good place to start. Good luck and please report back with results and pictures if you have that ability. Tim

[rgsjue]

Hey Tim thanks for the info, I am going to replace both so it is hopefully solved. I stopped by this summer with the 4wd silver van that you thought looked so clean and is. After this it will be the 4wd drive locking hubs that have been gutted so I am a little apprehensive.
Do you have a part # for the fan clutch and where is best place to get these genuine Toyota parts? Thanks again, Randy.

[llamavan]

Fan clutch ("coupling assy, fluid") is P/N 16210-73010 (same for all vans EXCEPT 1984).

Here's a few sources for parts:
1stToyotaParts.com (http://www.1sttoyotaparts.com/index.php)
toyotapartszone.com (http://toyotapartszone.com/)
LithiaToyotaParts.com (http://www.lithiatoyotaparts.com/partlocator/index.cfm?siteid=215542)

Because Lithia is local to me (Springfield, OR), I've done all my ordering from them for several years now,. Their internet site is fairly new. They are quick to let me know if something is no longer available, and because I can pick up locally, I don't pay shipping.
I've had good and not-so-great service from 1stToyotaParts. One problem has been waiting around forever to find out something is discontinued, but they have fast service otherwise. My biggest beef with them is that shipping is always a % of the total order price, even for lightweight parts.
No personal experience with toyotapartszone.

Gwen

[timsrv]

Hi Randy! I'm glad you found the forum. Llamavan is correct, the part number is 16210-73010. I see it lists on 1stToyotaParts.com for $94.26.

My favorite place to buy Toyota parts is Tonkin Toyota in Portland, OR, but sadly they dropped their internet parts site. I purchase enough to be on a 1st name basis with the parts guys there, so as a courtesy they still sell to me using the internet price structure. I'm speculating a bit here, but I'm guessing if you went in there and asked if they could match 1stToyotaParts.com's price, they would probably do it.........even if they didn't, at least then you could avoid shipping charges.

Like Llamavan, I have had the same exact experience with 1stToyotaParts.com. I've received absolutely awesome service on one order, then got completely forgotten about and screwed on another (usually due to some part that is NLA). I had to call them once about an order that I had waited 2 weeks for. Turned out the whole order got put on a back burner because of a stupid shift boot they couldn't get. All they had to do was email me or call and I would have told them to just ship the rest and forget about the boot. Then there's the 10% shipping with a minimum of $9.95 regardless how small and light the package (it sucks to get charged $9.95 S&H for a stupid $1.00 O-ring they could have put in an USPS envelope for 43 cents. I could almost see it if they did the same for heavy items too, but no, they ding you extra when that happens. Due to these issues, I now only use them as a last resort. :swear:

[VanSurfer]

Not sure if parts have already been acquired, but thought I'd at least post my experience with http://www.toyotapartszone.com/. They've been helpful on orders, website is easy to follow (especially when you type in your VIN), and pricing seems to be as good as it gets. My LD usually has no interest in ordering parts for me and quote me the highest price they can and tell me it will take 1-2 weeks (at least) to get parts, and this is after they roll their eyes. Cheers, Adrien.

[timsrv]

I was playing around the other day and came up with this method of testing a clutch fan. This won't help you identify one that comes on at the wrong temp, but it will tell you if it is functional. If you try this I'd like to remind you that it's at your own risk. It can be very dangerous getting this close to moving fans, belts, and pulleys. Also, don't overdo it with the heat on the thermostat. This is a bimetal coil and can be damaged by excessive heat.

That being said, it was a fun experiment and a useful way to evaluate a fan in question. Enjoy

Click on the image below to view
http://i8.photobucket.com/albums/a23/timsrv/TVT%20pics/Engine/th_MVI_1488.jpg (http://s8.photobucket.com/albums/a23/timsrv/TVT%20pics/Engine/?action=view&current=MVI_1488.mp4)

[micah202]

...haven't seen any method that's quicker or more definitive!
...Imagine that-an '80's toyo mechanic doing something unorthodox:LOL2:

[timsrv]

Here's a safer way to test. Note, it's a hot day & the AC is on.


http://youtu.be/4sHCeyOrncA

[gushaman]

it almost seems like i can see the different speeds in the video, i can tell when it gets hot enough, the blades look faster

[Cirrus]

Hello All, a few days ago my cooling fan started staying on all the time. As in, when I start the engine its engaged and it never disengages. Fan clutch issue I imagine, but I am not sure how to diagnose what exactly the problem is. I checked all the sensor plugs around the T stat and they are not loose.
Any pointers would be much appreciated!
Thanks,
John

[timsrv]

Sounds like it's time for a new fan clutch. There is a thermostat coil on the front that rotates a shaft. That shaft is probably stuck. You might be able to lube & free it up, but I would consider this a disposable part and simply replace. These typically last 150k miles. If the old one made it that far it doesn't owe you anything. A stuck fan clutch won't hurt anything except your power and your gas mileage. You can expect to see a 3 mpg or more drop with a stuck fan clutch. Tim

[Cirrus]

Thanks Tim..... I will check it out.
John

[foreverly]

That's really funny. My fan probably started to stay on right about when yours did. I bet the temperature change & contraction has something to do with it.

I will say I'm not too upset with my fan being stuck on. I haven't had heat soak once in these 90+ temps.... I'm not really noticing a change in gas mileage; I probably burned just as much stomping on the gas pedal every time I had heat soak.

[Cirrus]

Went ahead and replaced mine, now that I have a working one I don't think the old one ever turned on since I've owned (3 months) it until the few days before I replaced it when it was stuck on. The old one was packed with dirt in the metal coil from PO's trip to Baja. I am holding on to the old one as a spare in case the dirt was the only issue.

[F22hb]

Is it typical that they get stuck 'on' when they go bad? Do they ever break the other way?

[timsrv]

The typical failure is they won't come on.............which leads to overheating. It's better when they stick "on" but not typical. Tim

Here's more on clutch fans: http://www.toyotavantech.com/forum/showthread.php?1725-Fan-fluid-coupling-(fan-clutch)

[ratatouille]

Noticed my fluid coupling assembly (fan clutch) spins independently from the water pump pulley. Is this normal? Should the fan spin without the pulley moving? May be a dumb question...sorry.

Thank you.

[timsrv]

The fan clutch will allow the fan to spin at a different speed than the water pump. There is a bimetal thermostat coil on the front of it. When it gets hot (around 200 deg F) this coil moves enough to start changing the valving inside the clutch. It's a variable change that's linear to how hot the t-stat coil is. Typically the fan will spin whenever the engine is running simply due to centrifugal force, but unless the thermostat is engaged it will spin much slower than the pulley (freewheeling). When the temp gets high and the valving changes, the silicone goo inside gets restricted (this makes the clutch engage). The more it engages the faster the fan spins and the faster it spins the more air it will move. When more air moves there's more heat transfer from the radiator to the passing air. As the air gets cooler, the valving opens and the fan begins freewheeling again. The purpose here is to only turn the fan on when it's needed. Fans that run 100% all the time rob fuel economy and horse power. They also make a lot of noise. A correctly functioning fan clutch is a wonderful thing

Due to the placement of the radiator and the air flow characteristics in the engine compartment, the clutch fan is one of the most important parts of the cooling system. Due to the viscosity of cold silicone, it's normal to hear the fan engage for the 1st minute or so when the engine is cold. After the silicone is warmed up you shouldn't hear it engage again until your temperature needle hits about half way on your temp gauge. Then it should run briefly and the needle should return to about 3/8 of the scale. It may not run at all during the winter, but it should definitely see some action in the summer.............especially if you have working AC. Here's some pics of the internal workings of a clutch fan.

Here's the bimetal coil
http://i8.photobucket.com/albums/a23/timsrv/ClutchUnit.jpg

Here's a bimetal coil reacting to heat
http://i8.photobucket.com/albums/a23/timsrv/TVT%20pics/cooling%20system/Bimetal_coil_reacts_to_lighter_zps847104b8.gif

Here's a clutch that's opened up
http://i8.photobucket.com/albums/a23/timsrv/OpenedUp.jpg

The black propeller looking thing is directly attached to the bimetal coil. The coil moves this when temperature changes. Depending on it's position, it can block or allow the silicone's passage through the slots in the disc I'm holding.
http://i8.photobucket.com/albums/a23/timsrv/T-statValve.jpg

[ratatouille]

Awsome info Tim. Thanks. That clip of the coil reacting is great. I got worried when I noticed for the first time the fan spun without any other mechanics moving. I think I read in other thread somewhere someone was fixing their fan clutch because the fan wouldn't roar on a constant basis. Good to know now, it shouldn't be.

Any tricks or tips to inspecting while still connected and a cold engine?

It's going to be several days before engine is running and I have fan and belts back on.. In the past, I haven't had temp issues, I have working AC, & I don't think I have any problems here now. But wanted to check if possible while I have things opened up changing belts.

Thanks

[timsrv]

A correctly working fan clutch will roar for a few rev's while cold, and roar again when it kicks in. Most motorists don't notice stuff like this, but if you're paying attention you can hear it (especially When revving the engine while stopped with the window down). But since you haven't had any overheating issues, it's almost a certainty the fan is working correctly. Tim

[timsrv]

For obvious reasons it can be dangerous testing these fans & clutches. So I'll start out with the obvious warnings: There are moving parts here and you can get hurt! Keep your hands away from the moving parts! Don't try this at home! If you disregard and do anyway, you do it at your own risk! Okay, nuff said. Here's how I test clutch fans. The 1st video is of poor quality but good enough to get the point across. In order to start it just click on the picture below:

Click on the image below to view
http://i8.photobucket.com/albums/a23/timsrv/TVT%20pics/Engine/th_MVI_1488.jpg (http://s8.photobucket.com/albums/a23/timsrv/TVT%20pics/Engine/?action=view&current=MVI_1488.mp4)

The video below is a little better quality & shows a working fan (testing this way takes a little longer). Sorry about bumbling around.......I get absent minded/distracted at times :dizzy:.


http://youtu.be/4sHCeyOrncA

[Flounder]

Excellent videos, Tim - thanks for those! I have a fan clutch or two needing to be rebuilt. Is there anything special to watch or adjust while rebuilding? How much silicone should be added? Should that o-ring around the inside perimeter of the clutch be replaced? I'd think that that's probably where the silicone leaks out. As always, thank you all in advance for your advice.

[timsrv]

IMHO these are not worth messing with. I have a Toyota part number for the silicone goo, but no information as to how much to put in there. If you have one that's malfunctioning I would consider it disposable and buy a new one. I believe you can still get these from Toyota for around $150 or you can purchase aftermarket for around $40. I'm running a cheap aftermarket one right now and it's performing well. Tim

[chrismael]

I think this may be my next project (issue to be solved). My fuel economy dropped from 24 to 16 recently. I am running a bigger tire and have a low profile solar panel on the top but I think the TPS was also to blame. I replaced that, reset timing and am now getting 19mpg. I am extremely conservative in my driving habits and I fully expect to get back up above 20mpg on the highway. My 22-re pulling a 4wd king cab with canopy would get 24 highway / 26 on good stretches.

Am I unrealistic in my hopes for the 4yE fuel economy?

Thanks for the video and testing scenario Tim. They are very helpful. Oddly I have been fighting an overheating issue too.

I do have one remaining question for anyone....
When I installed the TPS, why are the screw holes slotted? Was I supposed to calibrate or adjust this somehow in relation to the stop screw on the other side? I don't recall the shop manual addressing this at all.

Thank you.
Chris

[timsrv]

Thanks for the kudos :wave2:. For the TPS to function correctly it must be correctly adjusted. For all intensive purposes a new (but out of adjustment) TPS is no better than a failed TPS. There's a video link at the end of my 1st post in THIS THREAD (http://www.toyotavantech.com/forum/showthread.php?1242-Article-Cleaning-the-Throttle-Body) that shows how to set it up. If you just want to check it without removing the throttle body, I show how to do that HERE (http://www.toyotavantech.com/forum/showthread.php?57-Engine-Service-Connector-not-working-can-t-set-proper-ignition-timing&p=395#post395). Good luck & have fun :thmbup:.

BTW, it's much easier pulling the throttle body back off after a recent service. Based on your mileage improvement, it sounds like you may have accidentally got close to the sweet spot, but I'd still want to take it off and recheck. If you really don't want to do that, you could check the ECU for codes. If the TPS code hasn't come back, then you might be okay (your call). Tim

[timsrv]

Update on aftermarket fan clutches. My TRW clutch I purchased at Napa made it almost 15k miles before it lost all it's silicone and quit working. Next I purchased a Hayden unit off of Rockauto.com (http://www.rockauto.com/en/catalog/toyota,1986,van,2.2l+l4,1279751,cooling+system,rad iator+fan+clutch,6812?a=Referer+www.toyotavantech. com+URL+%2F) and that one only lasted 5k miles. It was leaking almost from the beginning and finally quit engaging last week. I just purchased an Aisin (OEM) off Rockauto and will be putting it on tomorrow. It cost around $75 but I expect it to last for a long time. Tim

Check out the label on the box. It even has the part number that Toyota calls out for this application #16210-73010.
http://i8.photobucket.com/albums/a23/timsrv/TVT%20pics/cooling%20system/IMG_3569_zps78cf41de.jpg

http://i8.photobucket.com/albums/a23/timsrv/TVT%20pics/cooling%20system/IMG_3570_zpsd8e8577e.jpg

http://i8.photobucket.com/albums/a23/timsrv/TVT%20pics/cooling%20system/IMG_3571_zps92ef8491.jpg

[Reducto]

That looks exactly like the OEM one I installed a few months ago. It's the one on the right in this picture:1974

[JDM VANMAN]

Is the fan clutch the same for 2wd and 4wd vans? I've had a bunch of worked preformed on my 4x4 van and I know Tim had mention to keep a healthy and cool running system. I haven't replaced the fan clutch but wanted to order one up so when it's time to replace it it'll be on hand.

Thank you😊

[timsrv]

At one point I think there were 2 or 3 different OEM part numbers for these. All would mount the same (interchangeable) so not sure what the difference was (suspect the 4wd ones were a bit more heavy duty?). I haven't checked lately, but I would assume they all cross over to the same part number now. Even if they didn't, I'd still get this one off rockauto than pay double for the one that comes in a Toyota box (I'd consider this Aisin to be every bit as good as one from Toyota.......probably the exact same thing). Tim

[mr_josh]

I have to say- everyone has their opinions about things like non-OEM thermostats, non-OEM gaskets, etc., but the fan clutch is one thing where I think it's easy to see the difference in quality. When I first got my van, the OEM fan clutch was toast and I just needed something that would let me diagnose other parts of the van. Bought one from AutoZone and it's currently on its way out; has about 20k on it. Will be either rebuilding my original OEM unit or purchasing a new Aisin brand.

[ratatouille]

Hey Tim, How's that Aisin 75$ aftermarket working since you posted? About to finally pull trigger on one...

[timsrv]

It's been awesome so far (no leaks and it engages at appropriate times). The Hayden aftermarket clutch was leaking from day one. I can't believe what a fricken mess that thing made. Talk about the sh*t hitting the fan. Had just overhauled my engine, polished my manifold, painted, cleaned everything spotless, and only 5k miles later there was this nasty black mixture of silicone goo and road grime all over everything. And since the fan sits in the very front, it literally covered EVERYTHING. Of course this silicone stuff is not easy to clean off (nothing cuts it). The stuff that worked the best was silicone spray, so I used that. I finished that job about 2 or 3 k miles ago. I've been meaning to post, but have been putting it off.

Here's some pics of the old one (if you consider 5k miles old) and the mess it made:

http://i8.photobucket.com/albums/a23/timsrv/TVT%20pics/cooling%20system/IMG_3631_zpsaea00b44.jpg

http://i8.photobucket.com/albums/a23/timsrv/TVT%20pics/cooling%20system/IMG_3633_zpse888fdec.jpg

http://i8.photobucket.com/albums/a23/timsrv/TVT%20pics/cooling%20system/IMG_3634_zps5aef59ce.jpg

http://i8.photobucket.com/albums/a23/timsrv/TVT%20pics/cooling%20system/IMG_3635_zpsa459d488.jpg

Here's the new one ready to go back in:

http://i8.photobucket.com/albums/a23/timsrv/TVT%20pics/cooling%20system/IMG_3638_zps4c9b0e62.jpg

And here it is all snug in it's new home:

http://i8.photobucket.com/albums/a23/timsrv/TVT%20pics/cooling%20system/IMG_3647_zps724cfd00.jpg

[ratatouille]

Thanks Tim for sharing. I'll be putting mine on a few days when it arrives. Everything on my cooling system has been upgraded or replaced except the clutch. I've been suspect about the thing. No overheating still, specially after I upgraded to a high efficiency radiator, but I've ran the tests you suggested and I'm gettin' mixed results. I'd like to drop that temp needle as far as I can..ha.

[micah202]

just watched your Youtube,,, https://www.youtube.com/watch?v=4sHCeyOrncA


....I was very surprised to see the fan clutch engage at half heat,,

which brings up the question.... are the toyo temp gauges considered accurate?
....mine seem to usually engage the fan clutch at ~3/4 heat.



...and is there a way to test the clutches before installing?
,,,,I've recently gone through installing 2 different fan clutches,, both new,, both don't work!!:wall:

....would it work to heat the base in boiling water or on the heat element a few minutes?


Found a great price for a 3row copper radiator...$220.... http://www.partsgeek.com/ss/?i=1&ssq=%23W0133-1753530&x=21&y=10

[timsrv]

Did you read the previous posts in this thread?

[micah202]

.

...sorry Tim,, I read the whole thread,, interesting, but didn't answer my related questions.....

....I was very surprised to see the fan clutch engage at half heat,,
which brings up the question.... are the toyo temp gauges considered accurate?
....mine seem to usually engage the fan clutch at ~3/4 heat.


...and is there a way to test the clutches before installing?
,,,,I've recently gone through installing 2 different fan clutches,, both new,, both don't work!!:wall:
....would it work to heat the base in boiling water or on the heat element a few minutes?


​..it was good to see the difference between Hayden and Aisin in your review,, just in time to change my order! :thmbup:

[timsrv]

I don't know of a way to test a clutch fan other than installing and testing like shown in post #5. Personally, due to having multiple clutch fan failures, I don't trust used ones, nor would I waste my time installing. After dealing with that AM Hayden, I won't waste my time with AM fan clutches anymore either. I've been running the Aisin now for over 20k miles and it's still performing well.

As to your temp gauge question, they are not always going to read the same. To get a baseline on your gauge, warm the van up and put a meat thermometer in the fill port (be careful removing the cap as it might be under pressure). The van should be running between 180° - 200° F and your van's temp gauge should read between 1/4 - 1/2 travel. Assuming you're in this range (both measurements) then this is the norm for your van (make a mental note). If however your van is running below 180°, then you may have a stuck or missing thermostat. If the temp is good but the gauge is off, you may need a new sender or perhaps a new gauge. I personally like the digital Koso (http://www.amazon.com/Koso-BA024B11-Super-Style-Thermometer/dp/B0041QMS0E?ie=UTF8&psc=1&redirect=true&ref_=oh_aui_detailpage_o03_s00) gauges as they are very easy to read, accurate, and inexpensive (around $40). You can find them on Amazon. Tim

[micah202]

.


...thanks Tim,
,,that's a great way to calibrate the temp gauge and an Aisin fan clutch on it's way :thmbup:



...edit,, just called the local Toyo parts place about a thermostat,,, he said there's only one model,, opens at 203F, closes @180F ...that seems high for opening,, in fact I checked the thermo's I had and the toyo parts one was 180,, I'd go with your #'s Tim,,,
....but isn't it true that there's both summer & winter models?

[timsrv]

Use Toyota #90916-03046 180° F T-stat. The gasket you need is #16325-63010. Here's a good write-up that Gwen made that should help you replace it: http://www.toyotavantech.com/forum/showthread.php?21-Replacing-your-van-s-thermostat. Have fun :thmbup:. Tim

BTW, the Toyota T-stat begins to open @180° and depending on several factors may not fully open. If temp keeps rising, it will become fully open @ ~ 200° F. This is the only T-stat I use, and I use it year round.

[LightBlueToy]

My fan roars while revving at startup. However, I am not hearing it roar or seeing a change in speed once the van is at normal operating temperature driving around town, immediately stopping and lifting the lid to rev again. New fan clutch in my future?

My engine recently got hot driving up some grades in 95F heat so I have been trying to work on the cooling system. I have replaced the radiator cap and plan on putting in a new Toyota thermostat with AISIN gasket. I also ordered this electric pusher fan: Spal 30101505 12" Straight Blade Low Profile Fan (https://www.amazon.com/dp/B003PB9OJE/ref=cm_sw_r_cp_dp_T1_IL5Ezb6D70N9Z). I think at first I may just wire in a relay and switch directly to the battery so I can turn the pusher fan on and off from the dash for those more extreme situations. I can also use it to cool the engine bay down a little after turning the engine off. Researching the thermostat fan controllers online it seems like they are pretty hit or miss. They either fail often or people have issues getting them to activate the fan at the right temperatures. The flexalite one that seems the most reliable is over $100 and making my cooling system more robust is already going to be a multiple hundreds of dollars ordeal. Not sure if I should dig into replacing the water pump quite yet. Not quite ready to have the van down while waiting for my radiator to be recored or figuring out using the Griffin Aluminum one VanCo used. I am sure it needs it all though.

[originalkwyjibo]

The clutch fan is not designed to engage at "NORMAL" operating temperatures. Your engine will have to get pretty warm for it to kick in and then it is a varied degree of engagement relative to the air temperature coming off the radiator. According to Haydens (http://www.haydenauto.com/featured%20products-fan%20clutches%20and%20fan%20blades/content.aspx) website, a thermal fan clutch "Engages at about 170° radiator air temperature, (about 30° lower than coolant temperature)." I believe this would be the temp of the beginning stage of engagement. You likely won't get full engagemnet and roar until 10-20 degrees higher.

[LightBlueToy]

That makes sense, though I rewatched Tim's video and tried to replicate it with my van and it seems like I am not getting any roar like his:cnfsd:. I guess I was assuming (wrongly?) that since my cooling system seems to be on the weak side that revving at a standstill would make the fan roar. I ordered an AISIN clutch to replace mine anyway just in case, no idea how old this one is. Also ordered new Gates upper and lower radiator hoses.

[timsrv]

You can't go wrong with the Aisin fan clutches. Anymore, if/when I get another van with unknown history, considering the importance of this component, I would replace with a new Aisin and consider it preventive maintenance. I'd also replace the thermostat (just because) as I feel it's cheap insurance and makes me feel more secure about getting to where I'm going. BTW, that Aisin fan clutch I installed (earlier this thread) has over 40k trouble free miles on it now and is still working flawlessly.

Regarding the roar when hot, that will depend upon air temp coming out of the radiator. I'm not sure about actual air temps, but suspect it to be somewhere in the range original claims. Since there is a direct correlation between water temp and air temp, I would expect the fan to be 100% engaged @ around 200 deg F coolant temp. You can either put an aftermarket temp gauge on the van (to monitor) or you can put a meat thermometer in the coolant fill neck. Just remember that you're dealing with potentially dangerous stuff here. Keep your hands out of the belts and fan blades! Also be aware that removing the fill cap can result in scalding injuries. So please take appropriate precautions to protect yourself..........or just don't risk it! Tim

[LightBlueToy]

Glad to hear that AISIN fan clutch you put in is still going strong. I am excited to tear into replacing mine when it comes in the mail. Perhaps the roar will change after replacement or I need to more accurate temp monitoring like you say to really tell what is going on. I have been meaning to at least get an IR laser thermometer thing. Either way good insurance putting a new one in like you say.

On the topic of aftermarket temperature gauges I have been doing research on what to install in my van. I will post some things I have come across over in the Cooling system Mods (http://www.toyotavantech.com/forum/showthread.php?2759-Cooling-system-Mods&p=29202&viewfull=1#post29202) thread so I don't muck this one up too much.

[Usaviator]

I just got my van out of the shop after a lot of work to cooling system. Had my radiator sent up to Ability Radiator in Yuba City, CA for high efficiency core rebuild, new filler cap and housing, new head gasket replacement after that was confirmed as failed. Just driving the van from the shop to my place. Definitely did a lot better than before, but not quite cool enough on the temp gauge to make me 100% happy. My overheating problems before were an absolute nightmare. I would be driving 17 minutes to work, climbing up a hill towards the end, and then getting off the exit and almost as soon as I came to a stop light, my temp would creep up pretty quick and if I didn't shut it down right then and there, it would redline. It actually did redline a few times, hence my burned out head gasket. I was loosing way too much coolant through that breach, so the pattern was, temp would creep up, and then when I came to a slow section of road or got caught in traffic, it would just rise to the redline. It was a fast death for my headgasket.

Now I've got a lot of my ducks in a row on this one. The normal day driving temp in San Diego now is just barely below half (9/20ths I'd say), and when climbing larger hills, it creeks up to a little above half, but not quite a full 2/3. Maybe like 3/5ths. Only difference now from before is once up on top of that hill and turning off the highway and getting caught in traffic, is it makes a recovery back down to just below half. I have definitely seen this needle down to the 1/3 or 2/5ths mark at normal operating temperature in this van's prior life. So although a lot has been fixed and I'm feeling kind of good about that, I've had too many overheating experiences to not be cautious of failing in a different area. I looked up fan clutch and it brought me to this thread. Do you think based on these symptoms, it would be beneficial for me to replace it? I was thinking of getting the Aisin as Tim pointed out after having good luck with it. It may be almost twice the cost of the Hayden, but if it's half the headache, than it's worth it :thmbup: I also plan on attempting to replace the clutch myself. I've never done this before, but I'm pretty mechanically inclined. Is there anything special to know about this particular one, or does anyone have a tutorial on how they did this? Would it be beneficial to look up how to replace fan clutches on various car models, or is there something about this one that makes the directions very specific?

[bikerjosh]

Personally I don't trust the water temp or oil pressure gauges. IF it were my car, I'd invest in an actually gauge to read coolant temp, then go from there. I realize you have a history w/this van and experience watching the temp needle in different environments but I'd first make sure you know where you are at currently.

[llamavan]

[...] fan clutch [...] Do you think based on these symptoms, it would be beneficial for me to replace it?

Based on your initial symptoms (before HG replacement), YES.

But, based on your recent issues, perhaps not. I would still replace it if it's history is unknown (especially if it's possibly original). They're affordable and they do wear out.


I also plan on attempting to replace the clutch myself. I've never done this before, but I'm pretty mechanically inclined. Is there anything special to know about this particular one, or does anyone have a tutorial on how they did this?

I can personally assure you that it's so easy a girl can figure it out. :lol: Removing the passenger side access panel (http://www.toyotavantech.com/forum/showthread.php?26-Accessing-the-van-engine!&p=123&viewfull=1#post123) will allow you to remove the fan shroud and see what you are doing (reassuring if you're a noob), but is not necessary. The fan needs to come off the clutch, then the clutch comes off the water pump. The latter can get interesting because sometimes one or more studs come out of the water pump instead of the nut(s) coming off the stud(s), and you likely will have to grip the belt (careful, don't pinch your hand between belt and a pulley) to break the fan clutch nuts free. But it's all easily addressed.

Gwen

[Usaviator]

So I lifted up the drivers seat just to get a look at the fan and see what I'm working with here, and I noticed something strange... no fan shroud. Is that a problem? I think it was there before, but now I'm not totally sure if it was there or not or if my mechanic accidentally forgot to put it back on. I understand it could be a problem for sticking your fingers in there, but does it have a purpose to cooling the engine better? Isn't it supposed to hook onto the radiator and direct the air directly through it? Anyways, just wondering your thoughts on this. I'm sure this is a noob question since I'm pretty sure almost every car has a cooling fan shroud, but I never thought as to whether it made a difference in the cooling system or was only there to protect you from sticking your fingers in there.

[LightBlueToy]

Yeah you want that fan shroud in there for sure

[timsrv]

Since our radiators are up behind our floor boards, the shroud is a critical part on our vans. For the radiator to transfer heat it needs to have air flowing through it. Without the shroud air will take the path of least resistance..........& much of it will bypass the radiator. To exasperate the problem, the fan will be getting cooler air and will not kick-in fully. In short, it doesn't matter how good your radiator or fan is if there's no shroud to direct air through the right places. Tim

[Usaviator]

Ahhh, thank you for that. Very good news. I think it was running cool enough I can make it back to the shop. And I called my mechanic and sure enough, he had a shroud lying around he was wondering where it went. Between the new fan clutch coming in and the shroud being put on, I'm fairly certain that this will cover all the bases on my cooling system and this will finally run nice and cool.

[LightBlueToy]

Changed my fan clutch today. PO had an aftermarket one in there. The finned body part of the AISIN is definitely thicker. Makes me feel better about it.

[Ace MM]

, climbing up a hill towards the end, and then getting off the exit and almost as soon as I came to a stop light, my temp would creep up pretty quick
Sounds like my commute...

I recommend an external temp gauge, also for the trans.
I would not of fixed the issues had the PO not installed one.
I was able to correct them before the HG suffered.

[Usaviator]

There are so many things I could think of doing on this van. It's in pretty great shape really, but of course there is an endless amount of work and upgrades I could put on it, but me and my wife are moving cross country in a couple months, so this van needs to sell in the next month. I will be listing it on here as well as craigslist within a week or so.

[scotty]

Ran across this write up on Toyota fan clutches. I'm not sure if it's already on the site someplace or if it's even applicable to the 80s van fan clutches, but it seemed worth a read.

http://neuralfibre.com/paul/4wd/tuning-and-understanding-your-toyota-viscous-fan-clutch

[LightBlueToy]

That was informative thank you. Gets me thinking on whether I would go to the trouble of adding silicon or to the trouble fabricating a shroud for electric fans and wiring them in. Next time my clutch gets weak that is. Funny that there was person in the comments with an overheating 87 toyota van

[timsrv]

I agree that aftermarket brands might not measure up, but come on, do you really think some guy bumbling around in his garage has learned more than the engineers who designed this clutch? I'm sure his "scientific" calculations as to the exact volume of silicone would far exceed theirs....... :yes:. Regarding silicone levels, if you end up with not enough silicone, the fan will slip (won't move enough air). If you end up with too much, it will not disengage. If I had to guess, I'd speculate he has hydraulically locked his clutch. Yes, this would be better than a clutch that doesn't engage, but it would unnecessarily rob power and decrease fuel mileage. IMO opening a working clutch in an attempt to improve is a silly waste of time. I understand these tactics become necessary when things break and parts are NLA, but when you can get a new OEM clutch for ~$90, it just doesn't make sense.

These OEM clutches last about 150k miles. Considering what they do and the extreme environment they operate in, I say replace with a new OEM unit (Aisin) every 150k miles (or when it malfunctions) and forget about it. Tim

[Kyle]

Does anyone have any tips for how to actually remove an old clutch? Mine seems pretty helplessly stuck onto the shaft.

Been broken down in Wyoming for a couple days with overheating issues.

*update*
... nevermind, obvious answer is a big enough pry bar

[micah202]

Does anyone have any tips for how to actually remove an old clutch? Mine seems pretty helplessly stuck onto the shaft.

Been broken down in Wyoming for a couple days with overheating issues.

*update*
... nevermind, obvious answer is a big enough pry bar


ugh,, sorry to hear about the breakdown,,, hopefully you're sorted and rolling now.

[bushcat]

Do you need a special wrench (and or any special tools) to remove the fan clutch on these vans? I think mine needs replacing.

[Tan Van]

Ordinary tool sets probably won't reach it, but, the guy across the street is a Honda mechanic and had 2 really old box-end wrenches that were super long and thin... both were 6-point 10mm wrenches with only a one-sided wrench and just a long shaft on the other end ... about 12" long... the "Honda" brand wrench was close but no cigar, and the "Snap-On" brand wrench had more offset and just barely worked. With it I was able to pull the clutch and fan off the water pump without moving anything else at all. It would be worth buying one long wrench if you can't borrow. The 4 nuts were already a bit rounded from some previous butcher, but, you can reuse the fan-attaching nuts for the "clutch-to-water pump" studs and buy new flanged nuts for the "fan-to-clutch" studs. I was able to wiggle the clutch and fan as one piece in and out of the bottom of my 2wd van... which now makes me wonder if my entire shroud is still in place.

Update:

Wow---it's missing... (The bottom piece of my shroud)

[bushcat]

Ordinary tool sets probably won't reach it, but, the guy across the street is a Honda mechanic and had 2 really old box-end wrenches that were super long and thin... both were 6-point 10mm wrenches with only a one-sided wrench and just a long shaft on the other end ... about 12" long... the "Honda" brand wrench was close but no cigar, and the "Snap-On" brand wrench had more offset and just barely worked. With it I was able to pull the clutch and fan off the water pump without moving anything else at all. It would be worth buying one long wrench if you can't borrow. The 4 nuts were already a bit rounded from some previous butcher, but, you can reuse the fan-attaching nuts for the "clutch-to-water pump" studs and buy new flanged nuts for the "fan-to-clutch" studs. I was able to wiggle the clutch and fan as one piece in and out of the bottom of my 2wd van... which now makes me wonder if my entire shroud is still in place.

Update:

Wow---it's missing... (The bottom piece of my shroud)
It was 9 degrees this morning so I don't care right now, but, a Spring-project is in the plan...
If anyone has a cool home made shroud-bottom can you post a photo and a "how-to" ?


Thanks TanVan. Looks like the autoparts store rents fan clutch wrenches. Do people usually replace the water pump when down there?

[Grappler]

HISTORY — Just finished fixing all culprit issues associated with overheat, fan clutch, belts, water pump, radi cap, thermostat, hoses. Runs just fine and behaves normally EXCEPT ...In traffic or other warm-running situations, the gauge creeps. In Los Angeles, this is going to be a double-whammy issue as spring/summer approaches, so I want to figure it out right now. My fan clutch very audibly is engaged after a cold start, so I know it CAN work, the thing is, after the temperature gauge gets past half, I never hear it again and a quick test right after I shut it off gives no resistance. Soooo, is it possible that the clutch in there is just a dud? Could I have done something dumb or wrong? is not enough hot air getting to the bimetal tstat? (radiator clogged up?) It's a brand new (less than 500 miles) Aisin clutch from RockAuto.

HISTORY, PART TWO -- I was sitting in low speed traffic, and the thing did come on right after the temp gauge hit halfway --- hmmm. It's worth noting that it's never overheated, but it's gotten too close for my comfort on several occasions, usually at around 25 mph on a congested freeway. Before I did the work, the temp gauge would live at 1/4 of the way up (presumably from a stuck open thermostat.) Any thoughts? Am I just being scared over nothing? My next step is to blast the front of the clutch with a heat gun and see if the bimetal moves predictably.

RESOLUTION — I did learn a bit about fan clutches and, at least in my case, the Aisin FCT-37 I had (with the red mount) never worked in my 2WD auto application.

I discovered this after being (again) hyper sensitive about the van cooling, and noticed that no matter the situation, the red back clutch never activated unless it was a cold start situation, when the oil viscosity locked it on regardless. While idly online shopping, I saw that there was another AISIN clutch fan listed as fitting the van, the FCT-19, which has a black mount and seemed slightly smaller. I did some research and saw that it was listed as stock for the very early (2.0, likely) motors At the time, it was somehow listed on amazon for $15 (whoa!!) so I grabbed one just to experiment.

After days and days of garbage heat and me relying on the A/C, the new clutch fan works exactly as it should. It comes on post freeway drives, in stop and go, and when heat from the condenser gets to it. The FCT-19 is definitely physically smaller and less heavy duty (see side by sides below) but it works perfectly, so it's a keeper for me.

Has anyone else had this experience, used both, or did I really just end up with a weirdly defective AISIN product? It seems highly unlikely, but I can't explain it otherwise.

https://i.imgur.com/aRnS6BS.jpg?1

https://i.imgur.com/jwCqITr.jpg

https://i.imgur.com/2Z795lZ.jpg

[boogieman]

my aisin fan clutch seems to engage more often at a lower temp than needed, i thought at first maybe it was the aluminum radiator dissipating more heat onto it but that doesnt seem to make sense, i thought about trying to tweak the bimetal valve but decided to leave it alone as at least its erring in a safe direction...
the fan clutch in my 85 which doesnt get driven often is always engaged...i believe its an aisin as well, so i guess they fail in different ways...

[Tan Van]

my aisin fan clutch seems to engage more often at a lower temp than needed...

I bought 2 separate brand new Aisin clutches ,(red), that both ran way too long after startup-- sometimes for 2 miles or more in the dead of winter on every startup even when the engine was already warm...

I opened it up and drained about 5 or 6 cc's of the silicone fluid out of it and tried again. The new (RED) Aisin clutch just had too much fluid in it from the factory. I got lucky with my estimated quantity to drain because, now, the clutch fully engages only at startup -- it stops howling after about 15 or 20 seconds -- and, most importantly, I clearly heard it re-engaging this summer during really hot drives (high 90's and high humidity--freeway + street)!

This saved me from the "crap-shoot" of exchanging it and trying a 3rd new clutch all within 4 months.

(and, for reference, the van cooling system has no negative issues of any kind... and the front and rear heat also both work splendidly ---- the original clutch was always "locked on" which is why it was replaced ... and I expected the new aisin clutch to "fade out" after startup like it's supposed to, and it almost never did...and the replacement they sent was even worse... so, I saw the "silicone fluid tweaking" on a 4-runner site ---- and it worked.).

[dirtritual]

Use Toyota #90916-03046 180° F T-stat. The gasket you need is #16325-63010.

is Aisin OEM Toyota? or is Aisin aftermarket? ordering a few things from rock auto, but am confused on what's aftermarket or not. is toyota OEM only available from toyota?

getting the aisin fan clutch and figured it'd be a good idea to replace some things that haven't been done while I have the chance to. (i have very limited mechanic experience.. which is probably obvious haha) should i replace the coolant hoses or anything else just for good measure or inspect them first? or since the fan clutch is confirmed not working, should i do that first and then see where my temp gauge is at before replacing anything else? i don't really have time to waste as this is already effing up my plans, but I want to be thorough so i'm not having ANY overheating issues since I'm heading to the south.

[timsrv]

Toyota buys parts from several outside manufacturers. Denso and Aisin are two of the big ones. Denso and Aisin make parts for other manufacturers as well (not exclusive to Toyota). In many cases, when you purchase parts from Toyota, The only difference is you'll get a red box that says "Toyota" AND you'll likely pay much more $$$. For this reason, whenever I can purchase OE equivalent parts at discount prices that's what I'll do. In the case of this clutch fan, Aisin was the original supplier to Toyota, so Aisin/Toyota are essentially the same.

IMO, if you still have any original hoses they should be replaced. It's your risk though and also your budget, so use your best judgement. Good luck. Tim

[Carbonized]

as this is already effing up my plans,.

If I don't want anything effing up my plans, I make sure to plan around a thirty two years old appliance:roflmao:

[Yahshoor]

Can anyone who has driven both a TV and a Previa confirm for me that the fan on the TV should sound, at startup, like that of a Previa? B/c I have never heard that fan roar from my new-to-me TV. I recognize it from the fan-clutch-related YouTube videos, though.

[timsrv]

Due to several variables the sound would be a bit different, but yes, both are clutch fans and should have a roar at start-up that goes away after a few good revs.

[boogieman]

10226

decided i wanted to play around with a dead aisin fan clutch and did some research, land cruiser guys are using what called diff fluid for rc cars/trucks, its silicone and comes in many weights, and sold at hobby stores..most of the guys were using 10,000 cst weight oil, this ofna brand was the cheapest ($10 delivered for 4oz), looked of similar vicosity to a video i watched a guy using the actual toyota fluid...anyway i used about 2oz half the bottle, my clutch was pretty dry when i split it. fortunately all my clutches are working well at this time so ill have to get back on a report, but i think this could be a lifesaver if you were over heating out in the baran desert and needed to have the fan do more for you...

[micah202]

Yes, having hope of a spare fan clutch would certainly be on the list for a longer trip.
Wish I had one when I realized the mechanic had been wrong to assure me mine had been 'fine'. <;~l

[Mtn_Van]

For anyone that needs to remove/install the fan clutch for whatever reason, the extra long 10mm 12-point box wrench I picked up works wonders. No more worrying about rounding the four fan nuts if they're on tight and then having the fear set in about not being able to get the fan off. :LOL2: Also makes getting the nuts back onto the water pump pulley bolts a snap too. May very well be the best tool I've bought solely for my TV, so thought I'd share. Happy wrenching!

GEARWRENCH 10mm 12 Point XL GearBox Double Box Ratcheting Wrench - 85910 https://www.amazon.com/dp/B002V037SY/ref=cm_sw_r_other_apa_i_3WgZEb1G0JW5Q

[micah202]

Did a first start today, after doing a head gasket job, and it all looks sounds good so far,,, though brand new Aisen fan clutch seems continuously engaged....

I noticed even with engine cool, just starting up, the fan clutch seems to be engaged, and doesn't shut off.

...20 minutes at about 3,000 RPM, temperature gauge is at a quarter and the fan clutch is still engaged.
Median operating temperature usually shows the guage at center.

I don't remember seeing this before, seems odd. https://static.xx.fbcdn.net/images/emoji.php/v9/t6d/1/16/1f610.png

Red base, if that makes a difference.

VIDEO...
https://photos.app.goo.gl/wyp8DnQYkyhtyLH29

[timsrv]

It's in the nature of fan clutches to be engaged when cold as the silicone inside is too viscous to slip. There are variables as to how long it will engage cold depending on how hard you are revving the engine, but ~ 30 seconds of high revving should warm it sufficiently to slip/quiet down. After that it should stay disengaged until hot air from the radiator rotates the by-metal coil enough to change the internal valving. Many useful posts in this thread. Be sure to see post #19. Tim

[micah202]

I'll give it a try again today, but really seems like mine is waayy off.
Reminds me of the time I did a full rebuild, installed an OEM thermostat... which didn't open!! :dizzy:
It's important to be wary, whether we bought the best, or not.

[micah202]

How 'bout 20+ minutes @3000 rpm. Engine never managed to get above half of operating temperature.
I tested an older one as well. Got up to operating temperature no problem, and kept on going up, up, up. Doesn't function.


Parts Avatar in eastern Canada accepted a warranty return, but they told me they'd ''get back to me within 24-48 business hours'' with details for return... whaaat does that even mean! 4 daze, and tumbleweeds so far. 48 'business hours' over an 8 hour day,not including weekends,, and it could be 9 days before it starts it's 2 week trek across country.. then another 2 weeks for return post of a replacement. Glad I've got another vehicle. :dizzy:



It's in the nature of fan clutches to be engaged when cold as the silicone inside is too viscous to slip. There are variables as to how long it will engage cold depending on how hard you are revving the engine, but ~ 30 seconds of high revving should warm it sufficiently to slip/quiet down. After that it should stay disengaged until hot air from the radiator rotates the by-metal coil enough to change the internal valving. Many useful posts in this thread. Be sure to see post #19. Tim

[timsrv]

Yeah, sounds like you got a bad one. Usually when they fail they don't engage at all, and the result is overheating. At least you didn't have that issue. Good luck with the next new one. Tim