Factory fan clutch fluid replacement, still won't engage (2 Viewers)

[d0ubledown]

interesting. out of curiosity, if you know the hayden works, did you do the fluid change just for chits n giggles? are you going to be running the modded clutches instead? any opinion on the hayden vs a modded clutch with 6 or 10K fluid in it? im about to change my clutch, and thinking i might go the hayden route. but all the searches i find point to changing the fluid in either an oem one, or a blue hub. got a part # for the hayden?

 

[Tools R Us]

...
I kinda mis-spoke when I said I usually run in the desert. I avoid the heat, so when I run in the desert, it's not really that hot. I will find cooler spots to run in the summer, up at elevation. ...

Agreed, but I have to drive through the desert to get to the mountains.

... What I'd like to end up with is a fan that acts like an electric fan. I'd like to get the economy of freewheeling on the highway, but when I'm wheeling on a slow trail, working the engine, I'd like the fan to cut in as necessary and really pull some air so the engine temps drop fast. So I know I'll need a heavier oil, but I "think" I need to keep the cut-in point at a pretty high temp, like 110-115 degrees or so. ...

That is the setup that works very well on mine and others here. I don't remember what temp my valve is set at, but marked it stock, moved it around a bunch, cooler and warmer. Now it's slightly on the warmer side of the stock mark and works very well, has been there a few years.

At the time was running a bunch of temp sensors, intake air, fan output air, water temp, etc, when the motor was seeing load, thermostat open, A/C on, etc, the fan out temp was 130F+, have seen 160F+, so there is plenty of temp to kick it on when needed and don't see any advantage in running the fan when there is no load/need.

My default setup is 10K for the Eaton, black and early blue hub clutches with full shearing area, 14K on the later blue hubs with the crippled shearing grooves. I don't mess with the valve on any of them. We have done at least a couple of dozen like that and have never had a report of gas mileage or power loss, only better cooling and A/C vent temp.

 

[lacruiser]

Agreed, but I have to drive through the desert to get to the mountains.



That is the setup that works very well on mine and others here. I don't remember what temp my valve is set at, but marked it stock, moved it around a bunch, cooler and warmer. Now it's slightly on the warmer side of the stock mark and works very well, has been there a few years.

At the time was running a bunch of temp sensors, intake air, fan output air, water temp, etc, when the motor was seeing load, thermostat open, A/C on, etc, the fan out temp was 130F+, have seen 160F+, so there is plenty of temp to kick it on when needed and don't see any advantage in running the fan when there is no load/need.

My default setup is 10K for the Eaton, black and early blue hub clutches with full shearing area, 14K on the later blue hubs with the crippled shearing grooves. I don't mess with the valve on any of them. We have done at least a couple of dozen like that and have never had a report of gas mileage or power loss, only better cooling and A/C vent temp.

OK, so I should not mess with the timing on mine, just keep it whatever it was set at and just clean and replace the fluid with 10K stuff. That's what I'll do, along with a brand-new radiator. I guess while I've got apart, I may as well determine it's opening temp.

What Andy said: the spring shaft can get gunked and fail to turn the valve inside. Have you ever encountered that problem, if so, what to do? Is there some method of using solvent/cleaner, etc to get down into that area? I would guess not, as any solvent/cleaner might work it's way inside and contaminate the fluid and/or gunk up itself.

Can you dis-assemble these units enough to get in there and clean out the shaft to free it up if necessary? I would also guess not as well, but maybe some fresh silicone oil as a bit of lube from the outside might help a bit?

I'd really like to reuse this old part if I can, so if I can go inside and fix it to it's original spec for a few bucks, I will.

BTW, is there any consensus on the best oil to use? I know there are several hobby brands, from your and LandTank's experience, what is the best?

thanks

Dana

 

[Tools R Us]

UPDATE- I took the 10K filled clutch (left in pic), cleaned up the bimetal spring really good, pulled the end from the case (red arrow) and twisted it counter clockwise (looking down on it) just enough to where it didnt start the opening of the reservoir but about to, if that makes sense. ...

I have adjusted them by bending that tab, but only slightly and always stuck the tab back in with a dab of silicone. If you have a heat gun or hair dryer and an ir temp gun, it's easy to test the approximate opening temp. Blow hot air on the spring until the valve starts opening, then test the spring temp.

 

[Tools R Us]

...
What Andy said: the spring shaft can get gunked and fail to turn the valve inside. Have you ever encountered that problem, if so, what to do? Is there some method of using solvent/cleaner, etc to get down into that area? I would guess not, as any solvent/cleaner might work it's way inside and contaminate the fluid and/or gunk up itself.

Can you dis-assemble these units enough to get in there and clean out the shaft to free it up if necessary? I would also guess not as well, but maybe some fresh silicone oil as a bit of lube from the outside might help a bit? ...

I have replaced hundreds of clutches and have only seen a few that were mechanically bad (among good quality clutches, Aisin Eaton, etc), almost all died from the fluid going bad. My checks are; the bearing must spin smooth, free, the valve must return easy and no excessive leakage. Have only seen a couple that had stuck valves, all also had rusted springs, so maybe more common in rust belt areas.

The valve and bearing weep some silicone, so are lubed by it. It's a great waterproof lubricant, so they rarely fail, but if anything looks/feels sketchy, I opt for a new clutch.

...
BTW, is there any consensus on the best oil to use? I know there are several hobby brands, from your and LandTank's experience, what is the best?

thanks

Dana

Have used, Toyota, Associated, OFNA, Clearco and some that came in a no name tube, all have functioned the same.

 

[Tools R Us]

... any opinion on the hayden ...

At one time they made an extreme duty clutch that worked well, but is discontinued in the '80 application and was close to the $$ of a blue hub. I haven't seen anything close to the quality of the Aisin or Eaton units, so IMHO in this case, it's false economy to buy aftermarket.

This is reported to be a Hayden, proudly marked "Made in USA", puked the fluid in one summer. Note the small size, small reservoir, almost nonexistent cooling fins, only a flat area for shearing. Probably not a total POS, but not close to the quality units.

The Eaton is for size comparison, it had an unfortunate date with the bandsaw!

 

[Tools R Us]

Another aftermarket, unknown brand, looks good on the outside, large reservoir, good cooling fins, says "Made in Japan", has a blue dot, so like a blue hub? Didn't clean it, that how it came off of the rig, only lasted one summer.

Inside is disappointing, only has a flat area for shearing and the valve is all on or nothing. The shearing area should be very close, but not touching, this one rubbed turned the fluid black and killed it.

I would be much more confident running a mid nineties vintage Eaton with new fluid than ether of these new ones.

 

[Kernal]

Sorry if I missed it. Could someone comment on current production fan clutches - do they need any tweaking when new right out of the box?

What is the success rate of trying to revive a FZJ-80 fan clutch that doesn't seem to work (no roar)? I see no color on the hub, just aluminum, but it does appear to be large like the photos of an OEM clutch above.

Opinions on trying to bring the old one back to life vs just going with new?

Thanks

 

[landtank]

FWIW, after two years my clutch seems to have lost some of it's abilty and the weather really hasn't warmed up yet. I ran OFNA 5K in it. I just ordered some XRAY 6000cst which comes in a 35ml bottle. One bottle seemed to fill the clutch from a total drain just right. This was on a blue clutches.

On line the store is aa hobby or something like that and one bottle was something like 15.00 shipped.

 

[mikedamageinc]

This is interesting. The old spring looks pretty dirty, you did a nice job cleaning it up. what did you use?

I gotta think that gunk/rust has to interfere with the operation of the spring, so maybe cleaning the spring should be part of a clutch overhaul.

Now, about the part where you adjusted the spring.... It looks like you "unwound" it a turn or so? Is that what you did?

Seems that would really mess up the clutch timing.

Dana

You're right, I think a good cleaning should be part of the overhaul, I just used brake cleaner and a small wire brush but if I had some rust eater I'd probably use a little.

I didnt unwind the spring, just twisted a little to change the tension and put it back and it jsut took the shape that it did. It's not under much tension so don't worry about it unwinding.

 

[mikedamageinc]

interesting. out of curiosity, if you know the hayden works, did you do the fluid change just for chits n giggles? are you going to be running the modded clutches instead? any opinion on the hayden vs a modded clutch with 6 or 10K fluid in it? im about to change my clutch, and thinking i might go the hayden route. but all the searches i find point to changing the fluid in either an oem one, or a blue hub. got a part # for the hayden?

I wasn't actually sure if the clutch was bad (I didnt realize the roar was supposed to be a ROAR!) So I bought it to test it and to have a known good before tearing things apart. It turned out the fan clutches on both my cruisers were bad so I put the Hayden on one and started experimenting with the other.

The Hayden does the job but I would probably choose a new OEM if you don't want to do the fluid replacement. The Hayden has slots instead of bolt holes, I don't think it matters I just don't like the fitment. Also the flange nuts didnt fit and I had to grind them down a little, could have gone to the store but didnt feel like it. It came with new fan to clutch bolts, but not clutch to water pump nuts The Hayden is smaller as pictured and if you buy a new OEM, might as well go adjustable blue hub.

Napa and Pep Boys both sell the Hayden but it has to be ordered and you gotta pay the shipping so another reason just to give CDan a call for the Blue hub.

 

[mikedamageinc]

Sorry if I missed it. Could someone comment on current production fan clutches - do they need any tweaking when new right out of the box?

What is the success rate of trying to revive a FZJ-80 fan clutch that doesn't seem to work (no roar)? I see no color on the hub, just aluminum, but it does appear to be large like the photos of an OEM clutch above.

Opinions on trying to bring the old one back to life vs just going with new?

Thanks

Well it's up to you. With new parts you get a known good (for the most part). I would get an OEM blue hub if anything if I have to buy again, not another aftermarket just because of OEM reliability. But if you're like me and many others around here, you like to tweak things and do it yourself, then you might enjoy the fluid replacement. But after all is said and done, I'd rather have started with an adjustable blue hub.

 

[Tools R Us]

Sorry if I missed it. Could someone comment on current production fan clutches - do they need any tweaking when new right out of the box?

What is the success rate of trying to revive a FZJ-80 fan clutch that doesn't seem to work (no roar)? I see no color on the hub, just aluminum, but it does appear to be large like the photos of an OEM clutch above.

Opinions on trying to bring the old one back to life vs just going with new?

Thanks

A new clutch from Toyota is the Aisin blue hub type. They have less shearing area than the older black or blue type, but are very nicely made, quality units. For most uses they are fine as they come out of the box. If you run the rig hard and/or in a hot climate, changing the fluid will improve the performance. Here (desert, HOT) I rate them marginal at best in stock configuration, with the fluid changed to a higher viscosity they work very well. The higher viscosity fluid improves overall cooling capacity and lowers A/C vent temp.

 

[Kernal]

Tools R Us: thanks; (trying not to hijack the op's thread);
if the hub is just bare aluminum with no color, does that indicate a non-OEM replacement possibly?

 

[Tools R Us]

Tools R Us: thanks; (trying not to hijack the op's thread);
if the hub is just bare aluminum with no color, does that indicate a non-OEM replacement possibly?

The hub is steel, the Eaton and most aftermarket are unpainted, the Aisin is painted. Unless you know them well, the unpainted ones are hard to ID on the rig.

 

[Kernal]

I'll pull it off and look at it closer; thanks

 

[mikedamageinc]

Just another update. I just got back from a weekend trip, 3 hours each way, ~80F, A/C on, 65 MPH (avg), 10K 50mL fluid there, 6K 40mL fluid back.

With the 10K it seemed to run a little cooler with the needle about half way, barely above half on steep climbs, and regularly dropping to 1/3 for a few minutes then jumping back up to half way.

The 6K ran a little above the half way mark, also barely raising for steep climbs. This one only dropped to 1/3 once or twice.

What is the dropping and jumping in the needle, thermostat opening and closing? Someitme I'd liek to pull both clutches back apart and test to see what temp they actually open but I am sure that it is a two stage opening. I don't know if it was cleaning the spring and surrounding area or the bending of the spring that made these work or both but it was one of them at least!

 

[Kernal]

Anyone: The only oil I can find locally is OFNA (5000, 7000, or 10000). Is this a good brand or should I go with XRAY or some other brand as others have used? This will be going into an original ?Eaton clutch in a 96 model. BTW: what was the weight of the original oil used in these clutches?

 

[lacruiser]

Tools R Us, Kevin,:

I was thinking about another way to determine the opening temperature of the valve.

I was thinking about using a hair dryer on the thermostatic spring, holding a thermometer right next to it, gradually warming it up, and then noting when the valve opens.

Do you think you'd get a different reading than using the water method?
Are you still using the water method to set/measure the opening temp?

thanks

Dana

 

[Tools R Us]

Tools R Us, Kevin,:

I was thinking about another way to determine the opening temperature of the valve.

I was thinking about using a hair dryer on the thermostatic spring, holding a thermometer right next to it, gradually warming it up, and then noting when the valve opens.

Do you think you'd get a different reading than using the water method?
Are you still using the water method to set/measure the opening temp?

thanks

Dana

The method that I have had the best results with is: Blow on the spring with a heat gun (hair drier would probably work, but slower) until the valve is full open, turn off heat. Measure spring temp with an IR gun, watch the temp as it cools/valve closes to determine the temp at first opening.