New fan clutch oil replacement (red hub) - Update: swapped in stock green hub (1 Viewer)

[Infinity00]

Tested it again going up hill - outside temp was 70 deg instead of 90deg but it held at 206 deg on my mech temp gauge with the stock needle barely going to about 40% on the gauge. I don’t like it running at 206 (and that was with AC off) so even though I think this is working and the spike fake(!) I am glad I put an order in for the green hub. It’ll arrive on July 2nd and I’ll follow up with the performance then.

Here’s the part number for the green hub
FCT-049 $144 from amazon. It says it doesn’t fit the 85 fj60 but it does fit the 91 fj62. I’m pretty sure it’ll fit the 60 but I’ll edit this post if it doesnt.

 

[Infinity00]

Link to green hub
https://www.amazon.com/gp/aw/d/B008EEYLT0

 

[Infinity00]

Hi Jim

 

[Infinity00]

Alrighty, I got my green hub today and put it in. It’s thicker than the red hub but otherwise the dimensions look the same. It’s been 101 degrees here of late so tomorrow let’s hooe for another hot day to test out the new fan clutch.

I’ll probably dump the old oil out of the red hub and see what temp it opens up at, and add some much heavier weight oil.

 

[FJ Silver]

Nice! very curious about its performance. I'm in 110 degrees territory for a while so I need to make a move on the fan clutch soon here. Thanks for sharing

 

[Michael Hanson]

Hi, Just installed a new green ,Aqua Aisin hub with 10,000 oil ,I'm not impressed in this 104 degree weather. Mike

 

[Infinity00]

That sucks! Did you adjust it?

 

[FJ Silver]

Hi Mike,
Does the clutch not lock up when it should? and did you add the 10,000 oil or does it come with prefilled with it? Thanks

 

[Infinity00]

It’s cooled off here significantly so driving with the new fan clutch hasn’t been totally put to the test. That said, driving around town it was running cooler, under 200 deg, where the red hub was running closer to 200.

Driving up the hill, the temp went to 205 degrees, but dropped quickly when stopped. It was in the 80s today (ambient temp).

So far, I’m not impressed but I’ll leave it in and monitor for a little while as it heats up again this week.

 

[Infinity00]

Did some investigation into the red hub that I removed to install the green hub. I drained the oil - and a lot was missing. I had tightened it properly but I didn’t get out as much as I put in. My gasket is in good shape (brand new and wasn’t removed), all the screws were tight when I removed them - I needed my impact - so I’m not sure what happened or how to prevent it from happening again.

Pictures of the valve at different temps follow.

Summary:
It is closed at room temp, not quite half open at 175*, slightly more than half open at 225*, and full open at 238*

Room temp:

175*

225*

238*

 

[Spike Strip]

I've never had much luck replacing the oil in the red hub. I used some black RTV at one point and that did the trick, but I eventually just replaced with a new unit. I have a 3FE blue to go on later - The red clutch mechanism is crude compared to the 3FE unit. Not sure if it actually cools any better, just better built, and holds more fluid.

 

[Infinity00]

I was doing a lot of reading earlier today. The 3FE is the fj80 and the fan clutch is green. The FZJ80 is the blue hub from what I’m gathering. The blue hub has the adjustable valve, the green I don’t think does. Tools R US, I think it was him, likes the green when it has 10k fluid. For the blue, I believe the consensus is more or less adjust the valve to open earlier and change the fluid to 6k. Of course there is a lot of variation and debate about all of it. I’m leaving my green hub like it is for now and will see how it does over the next few weeks.

@Spike Strip - When you say the 3FE blue, do you know if you bought the fj80 or the one for the fzj80?

 

[Spike Strip]

I have the FCT-049, like the one linked above.

The red one works fine, it's just that they get a zillion miles on them and the oil shears over time. They wear out.

 

[Infinity00]

Yeah that’s the one I bought. It does have a slightly bigger holding area for the fluid and the bi metal spring looks beefier/better.

 

[Infinity00]

I finally was able to test the green hub in hotter weather and it’s still getting up to 205* on my climb home. I pulled it to add 10,000 cst and to adjust the valve to open halfway at 95* like I’ve read in the other threads. Sometimes they have put higher viscosity, but I think I’ll start with 10,000 and go higher if it doesn’t work.

I took my brand new red hub and refilled it, this time with 15,000 cst (7.5k preciously). First time I’ve heard any of these hubs roar! I think that is a better sign I’m going in the right direction. It was pushing the air like I haven’t seen in the stock red or green hub. After I let it run for a few minutes, it stopped roaring as the fluid was pushed back into cavity. For kicks I’ll see how the red hub does with the 15k, but I’ll be putting the green hub back in ASAP, since I’ve determined it is adjustable and I can add thicker oil.

I’ll follow up with my results in a week or so

Here’s my array of silicon diff oil I bought from the hobby store. I went a little crazy purchasing so much but it’s a good hour drive from my house and I don’t want to have to go back. After draining and baking the red hub, I was only able to get 30ml into it. One bottle of the Losi stuff. And some grey permatex to seal it up this time (probably overkill but I don’t care)

 

[FJ Silver]

Awesome! thanks for sharing your findings.

 

[FJ40Jim]

I found my vacuum line that opens the hot air flapper (HAI/HIC) had come off creating a large vacuum leak.
After a little while waiting for it to cool, I finally re-attached the vacuum line and fired it up with all heaters blasting and it cooled off again. But when I pulled the line off my flapper, it slammed shut, I assume down blocking the hot air intake, so reattaching it opened it. This doesn’t seem right, it should have no vacuum with the engine hot and the door should have been blocking the hot air intake. Inspect HAI/HIC system for correct operation of flapper when hot.

Since the truck is desmogged, disable the HAI during the summer.
Disconnect vac hose at air cleaner door, insert BB in hose and reinstall. Squeeze out BB if cold weather driveability is suffering.

Temp sender: does anyone know what the 23 stands for?

Part of the date code. Read the stamping on all sides for the date. The symbol next to 23 is the corporate mark for Yazaki Vox.

 

[Infinity00]

Thanks Jim, that’s what I ended up doing, once I figured out it wasn’t working. I worked on the HIC a little bit to get it semi working but keeping it plugged for the summer.

Okay, I pulled apart the new green hub and the earliest I can get it to open halfway is at 120*, this is with the adjustment rotated to its maximum limit to open at the lowest temp.

There are the 2 different valves that open. The smaller valves opens first and the larger valves open as the heat increases.

Factory setting:
Factory setting upon separating the 2 halfs of green hub, notice the adjustment screws are almost fully counterclockwise:

With the factory setting the smaller valve barely opens at 120*:

Post adjustment, screws rotated clockwise:
The screws are set to the maximum clockwise position, this adjustment should make the valve open at the lowest temperature. The lowest temp I can get the larger valves open to halfway is 120* and it closes off at 110*:

 

[LAMBCRUSHER]

that is going to get you fixed. that and some 12500+++ CSK. I found tricking it to open earlier solved almost all of my issues, mostly including my self induced balding...

 

[LAMBCRUSHER]

the more you need it to spin at idle and at higher speeds to fight higher temps, the higher the CSK you want to run...trade off is that too high a CSK and your fan will ROAR at 80 mph in 40*f temps and your gas gauge needle takes skydiving lessons...