Results w/Blue Hub Fan Clutch?

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Not to hijack this thread, but is there a place online to buy the oil? We live in a pretty rural area, no idea where we could find a hobby shop around here. thanks
 
landtank said:
I have swapped out a few clutches recently and one of them was the earlier black hubbed Aisin clutch. This is the clutch that is finned all around and when opened up it has the square hole for the first stage and a boot shaped hole for the second stage.

While there is more shearing area in the first stage the second stage is lacking severely compared to the blue clutch.

It's this second stage that provides the bulk of the drive to move the fan. ...
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Don’t understand what your saying? The only place where the fluid shears/produces drive is where the metal surfaces are close together. The purpose of ridges is to provide additional close surface area. The fluid circulation is radial outwards from the valve to the pump that returns it to the reservoir, it’s driven by centrifugal force, so when the main valve is open, all of the ridges are in play.

We have done tons of temps tests, etc, but in this case they aren't necessary. Most of the rigs that wheel locally have upgraded fluid in the clutches, for the last few years most with 10K fluid. On the trail, walk by a line of rigs, it’s hot, they are idling, waiting to be spotted or whatever. The ones with the early blue or black hubs will try to suck your laundry into the grill, have big air blowing out the fender wells, etc. The later blue hubs, not so much. It’s not a fair fight, at all, even the ones with big electric “bandaid” pushers don’t come close, a blind person could “see” it. All of the tests have shown that about double the viscosity is needed to make about the later blues blow about the same airflow as the black/early blue.

A pic of old vs. new, looks like ~twice or more area and which matches the observed performance difference.
blue_ridge.webp
 
landtank said:
I'm not sure what the eaton fan clutch looks like but don't assume because you have an older clutch you have a better one.
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landtank said:
so that is what the other one is. I thought that it was some off brand POS. I'll have to crack that one open and see what all the hubbub is all about. Funny thing that clutch was the worst one I've seen as far as resistance is concerned when first removed from the truck.
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I wouldn’t say that Eaton clutches are better than the Aisin, but are good, durable, serviceable clutches, much better than any aftermarket that I have seen. Haven’t seen a broken/bad one, have changed the fluid in many, some/most with over 150K mi, they respond well to a fluid replacement/upgrade and work well.

If you don’t want to take one apart, here are some pix of the insides.
eaton_1.webp
eaton_2.webp
 
The 240ºF temp is beyond dangerous!!

At SEA LEVEL water boils at 212ºF. The ONLY thing the radiator cap is there to do, other than hold in the coolant, is to RAISE the boiling point of the water/coolant mixture. Radiator caps are rated in pounds. For the 80s we all have a 12# radiator cap. For EACH pound of pressure, you INCREASE the boiling point by 3º. So for a 12# cap you are raising the boiling point 36º. So AT sea level, your cap goes pop at 248º thus removing all the pressure built up in the system and now that 248º instantly boils and wants to eject itself out of the radiator. If you are lucky its only a radiator cap. But chances are it will take other things with it; radiator, hoses, block, etc.

Now add say an 8k elevation to that equation. That's too risky for my blood. Highest I've ever seen was 217º and I wasn't too concerned because I new I was a good 10º before my A/C cut off.

As a rule of thumb, for every 500 Feet elevation, water boiling temp drops 1° F.
 
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:hhmm: I almost pulled the trigger on a new blue one. I dont have any issues with my current, and was thinking more along the lines of PM. Perhaps I should just service the one I have.
 
retrofive said:
:hhmm: I almost pulled the trigger on a new blue one. I dont have any issues with my current, and was thinking more along the lines of PM. Perhaps I should just service the one I have.
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I went ahead and got one ready to go from LANDTANK. I sent him my 10k CST and I will have it before my trip. The one I have now is good but I will keep it as a spare now.
 
FirstToy said:
Tools,
so for the old clutch, use 10k fluid.
new blue clutch, use 15k or 20k fluid for comparable results?
Click to expand...

In my experience, the results would be comparable, but it's not good to make a blanket statement that one setup, viscosity would work best in all climates? My experience is rigs mainly operated in desert conditions, I cant say how thicker fluid would work in subzero conditions.

Theory would say that the clutch is thermostatic controlled, so will be off until the radiator output airflow is warm enough to need it? My guess is rigs operated in subzero conditions would rarely or never see 140F grill intake temps, so wouldn't need fluid that thick? I don't have any experience with subzero temps, because I hate COLD!:hillbilly:
 
retrofive said:
:hhmm: I almost pulled the trigger on a new blue one. I dont have any issues with my current, and was thinking more along the lines of PM. Perhaps I should just service the one I have.
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Retro, I would not mess with your fan clutch, since you have a '94, unless your having cooling issues. Have you done RT's temp gauge mod? Reason I'm saying this is I checked mine ('94 also) and I've got the black hub Aisin which according to Tools, is one of the best stock clutches. I did the temp gauge mod so I can now get an accurate reading on the engine temp. My fan clutch is just like it was when Mr. T made it. And my engine temps stay under 200* while pulling grades on the passes here, with the A/C on this summer. For most of my driving the gauge shows a needle width under half (189*) with out A/C and right at half or a needle width over with A/C. The best thing you could do is the temp gauge mod., then you'll have an accurate handle on your engine temps and how effective your cooling system is for the driving you do. - My .02
 
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Thanks 80t :), Nope issues at all. I have the parts for the RT mod, just haven't installed yet. Guess its one of the those I read to much here on mud things. All in all my cooling system seems to be running well (knock on wood).


80t0ylc said:


Retro, I would not mess with your fan clutch, since you have a '94, unless your having cooling issues. Have you done RT's temp gauge mod? Reason I'm saying this is I checked mine ('94 also) and I've got the black hub Aisin which according to Tools, is one of the best stock clutches. I did the temp gauge mod so I can now get an accurate reading on the engine temp. My fan clutch is just like it was when Mr. T made it. And my engine temps stay under 200* while pulling grades on the passes here, with the A/C on this summer. For most of my driving the gauge shows a needle width under half (189*) with out A/C and right at half or a needle with over with A/C. The best thing you could do is the temp gauge mod., then you'll have an accurate handle on your engine temps and how effective your cooling system is for the driving you do. - My .02
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Duely noted...if it wasn't for my scanguage, it would not have realized just how hot the engine was running...the gauge on the dash was just about to the redline, but still in the "safe" zone. I am going to try replacing the oil w/10K in my stock Eaton and if that don't help than Landtank's blue hub will (provided its not the thermostat, coolant, radiator, ect.)

NLXTACY said:
The 240ºF temp is beyond dangerous!!

At SEA LEVEL water boils at 212ºF. The ONLY thing the radiator cap is there to do, other than hold in the coolant, is to RAISE the boiling point of the water/coolant mixture. Radiator caps are rated in pounds. For the 80s we all have a 12# radiator cap. For EACH pound of pressure, you INCREASE the boiling point by 3º. So for a 12# cap you are raising the boiling point 36º. So AT sea level, your cap goes pop at 248º thus removing all the pressure built up in the system and now that 248º instantly boils and wants to eject itself out of the radiator. If you are lucky its only a radiator cap. But chances are it will take other things with it; radiator, hoses, block, etc.

Now add say an 8k elevation to that equation. That's too risky for my blood. Highest I've ever seen was 217º and I wasn't too concerned because I new I was a good 10º before my A/C cut off.

As a rule of thumb, for every 500 Feet elevation, water boiling temp drops 1° F.
Click to expand...
 
Tools R Us said:
In my experience, the results would be comparable, but it's not good to make a blanket statement that one setup, viscosity would work best in all climates? My experience is rigs mainly operated in desert conditions, I cant say how thicker fluid would work in subzero conditions.
Click to expand...

I have my old clutch and also a new, blue clutch. The blue is in the truck now but I do know the truck is not pulling air into the grille as you describe it should.

I was thinking of putting 10k in the old clutch and replacing the blue one.

It makes sense what you say- if it's cold, it won't engage so the cold should not be a factor. Anyway, I'm in socal. Cold is 70F ;)
 
FirstToy said:
I have my old clutch and also a new, blue clutch. The blue is in the truck now but I do know the truck is not pulling air into the grille as you describe it should.

I was thinking of putting 10k in the old clutch and replacing the blue one.

It makes sense what you say- if it's cold, it won't engage so the cold should not be a factor. Anyway, I'm in socal. Cold is 70F ;)
Click to expand...

Agree, the fluid is cheap, so experiment and see what works best for your use/conditions.
 
retrofive said:
Thanks 80t :), Nope issues at all. I have the parts for the RT mod, just haven't installed yet. Guess its one of the those I read to much here on mud things. All in all my cooling system seems to be running well (knock on wood).
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Have the stuff ready and I'll do it up for you when I come up to visit! I've done a few of them already. Have you done the window up mod? If not its a good time to do it as well.
 
I just completed a thorough shakedown of my landtank modded blue clutch. Before the clutch, on hot days, climing steep freeway hills in 100 degree desert heat I was getting up to 225 degrees. Now I rarely break 200, with 209 being the very hottest I've been able to get it. I'm satisfied. I'm puttin a pusher on just to keep the AC temps down a little.
 
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