'Modding' Eaton Fan Clutch - How Much Fluid and Where?

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CorvetteFan

CorvetteFan

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The thorough (?) PM'ing of my '96 has cost me most of whatever was left of my sanity! Not to mention most of what was left of my money...

I'm down to doing the 'modding' of the fan clutch. The clutch that I have is original to the '96 'Cruiser... it is an EATON as best I can determine from reading the many Forum threads (TORX screws and the Eaton-specific internals).

I have the thing apart and have drained the original fluid out (the oven set at 200-degrees F works like a charm).

No matter how hard I search, I simply cannot find the answer to these two questions (photo below):

1. Do I put my new 10,000 fluid into both halves of the clutch, and

2. Approximately how much fluid will be required (I have 2 oz.)

Thanks,

Rob

CIMG3883.jpg
 
ERG80 said:
This is the thread I used when I did mine.
https://forum.ih8mud.com/79-95-toyota-truck-tech/167678-fan-clutch-service.html
post 6 has some tips.

I refilled to the bottom of the 3 circular holes in the half with the o ring. It would be good to measure how much came out and refill that much to see where it fills to.
Click to expand...

Thanks, ERG80, for the speedy reply! I saw that thread, but most of it (including Post #6) was not about the EATON clutch.

1. May I assume that yours is also an EATON clutch?

2. What 'weight' fluid did you refill with (I plan on 10,000)?

3. Did the 'mod' make a difference in cooling in your case?

Thanks again!

Rob
 
Best info and quickest response would be to PM Tools R Us with your questions. Kevin, IMHO, has the most experience on this forum with fan cultches and restoring them. I agree that most of the info in the threads is about the Aisin clutches and it's tough, if not impossible, to get the answers to your questions in the material that's already posted.
 
CorvetteFan said:
Thanks, ERG80, for the speedy reply! I saw that thread, but most of it (including Post #6) was not about the EATON clutch.

1. May I assume that yours is also an EATON clutch?

2. What 'weight' fluid did you refill with (I plan on 10,000)?

3. Did the 'mod' make a difference in cooling in your case?

Thanks again!

Rob
Click to expand...

1. yes.

2. I used 5k. (10k not available locally)

3. No, but I think my clutch was going bad. I had some noticeable bearing noise when it was empty and even with new oil there wasn't much resistance spinning it. Thicker oil would have helped but since it had the noise I decided to get a blue hub.
 
Tools R Us said:
Yes, it doesn't matter where you put it.



I use ~50ml in the Eaton.
Click to expand...

Well, I managed to get somewhere around 50ml into both halves... with the last 5ml or so just going onto the 'face' of the hub (back) half... I guess it will all wind up where it is supposed to be!

Question: Blue LOCTITE on the torx screws on reassembly or no?

I think that it's interesting that the 10,000 stuff that I put in doesn't seem to be much (any?) "thicker" than the OEM stuff that I drained out (but I suppose that it is hard to "estimate" things like that). However, there was significantly less drained out than new stuff that was put in.

Thanks.

Rob
 
CorvetteFan said:
Well, I managed to get somewhere around 50ml into both halves... with the last 5ml or so just going onto the 'face' of the hub (back) half... I guess it will all wind up where it is supposed to be!
Click to expand...

Put it where it fits, when first run it will be pumped into the reservoir, in the front half of the clutch.

CorvetteFan said:
Question: Blue LOCTITE on the torx screws on reassembly or no?
Click to expand...

I don't, but up to you.

CorvetteFan said:
I think that it's interesting that the 10,000 stuff that I put in doesn't seem to be much (any?) "thicker" than the OEM stuff that I drained out (but I suppose that it is hard to "estimate" things like that). However, there was significantly less drained out than new stuff that was put in.

Thanks.

Rob
Click to expand...

Yep, cst is a very small/fine step measurement, even the 30K doesn't feel/look that much thicker than 10K. It does make a big difference in performance. I usually put more fluid, in theory, will extend fluid life.
 
I first put in 6k and it made no difference. Put in 10k and it does make a difference, it doesn't go much above 195 going uphill on a warm/hot day.

One thing I'm miffed about - at the first start-up after putting in 10k I got the roar. Since then I no longer get a roar. It still works fine and has plenty of resistance but no roar. Not sure why.

edit: its an Eaton btw
 
skii said:
...
One thing I'm miffed about - at the first start-up after putting in 10k I got the roar. Since then I no longer get a roar. It still works fine and has plenty of resistance but no roar. Not sure why.

edit: its an Eaton btw
Click to expand...

I have noticed the same. My guess is the reservoir is better sealed and the fluid doesn't leak out as quickly, so little roar. It doesn't affect performance so :meh:, if a big startup roar is important to you get an Aisin.
 
Modded Eaton after thoughts

I realize this thread is a few months old but this reply relates to the overall modding of the Eaton fan clutch.

Yesterday I pulled my blue hub FC because I thought it had a bad o-ring. As it turns out it was fine, just my paranoia. But that topic is for another thread.

I pulled my old Eaton of the shelf and cleaned it up a bit, pulled it apart and drained out the original oil. Once "completely" drained i filled both sides with Team Losi 15K cst, ~50mL, as per Tools figure.

I put everything back together and went about my day. The temps were in the upper 80s to low 90s and at first things looked good. But as the day wore on, idle temps began to creep up (upper 190s as apposed to 190-193 with the blue hub) and temps in turn took longer to come back down. So this morning seeing as the blue was fine, I decided to swap them back out (I now have it down to about 10min). With the blue hub back in, I took a closer look at the Eaton and even with the 15K cst (same as the blue hub) the darn thing will free spin in my hand. I mean almost zero resistance.

So...I am not sure if I did something wrong with the refill process or perhaps I put to much in. Not really sure what went wrong. If anyone has any thoughts, I would be interested to see what the minds of Mud have to say.
 
I've just had the same experience with the Eaton that was on my '97 although I used 10,000cst. It worked better before the rebuild as witnessed by increased temps afterwards and practically zero spin resistance when really hot. Drained the thermostat side face down rather than angled up for two days in the hot sun and both sides were empty before being filled back up. Just bought a used black hub Aisin and installed with a 3FE fan and am seeing much greater cooling ability as well as increased noise but that is the price you have to pay, I guess, for better temp control.
 
has anyone tried filling more than 50ml's in the Eaton clutches?


I'm doing mine as we speak,

I'll probably go with 15K CST and I am thinking of pouring 60ML's in there, I haven't measured what came out but its a good amount of oil.
 
What is the OEM fill viscosity for the Eaton units? The blue hub is 5k cst and folks are replacing with 10k to 30k cst silicone, but perhaps Eaton was already using 10k or 15k and 20k or 30k would be more appropriate to effect noticeable and lasting performance changes.
 
Toyota doesn't publish viscosity or fill amounts for any of the clutches. So the only way to compare relative performance between the clutches is by doing, comparing modded clutches in like conditions.

The Eaton is a good clutch, but is a very different design, when compared to the Aisin clutches. It is much more civilized, doesn't roar like the Aisin does, but can be a very strong, durable clutch. If I had to rate them, with the same fluid in them, the black hub Aisin would be the strongest, Eaton in the middle and the blue hub Aisin the weakest. To perform the same, the black hub would need lower viscosity and the blue hub higher viscosity than the Eaton.

I run most ~15K, the highest that I have run is ~17K. This has worked well in desert conditions.
 
Ditto some of the above experience with the Eaton fan clutch. My cheapo Dayton fan clutch lasted 2 years then died suddenly.

Had my old Eaton, drained old oil and put in 50cc of 15,000 weight silicone oil and it did not work well at all!

Best bet seems to be the Aisin with blue hub. I bought a Landtank modded fan through AJIK Overland Exchange (AJIK Overland Exchange |) and that seems to be the best overall solution.
 
Wish I had found this thread earlier. I was convinced my fan clutch was not performing well, but it's an eaton unit and I only have 6,000 cst to fill it back up with. Maybe I should put the old oil back in it and keep running it?
 
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