The Fan Clutch (clutch fan / fluid coupling) Thread

[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


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 .

[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 . 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 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. Good luck & have fun .

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 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.

[Reducto]

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

[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:









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



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

[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!!

....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...3530&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!!
....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!

[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 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



...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/s...n-s-thermostat. Have fun . 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.