fan clutch help for 2f (1 Viewer)

[Bigcity25]

i have a 2f in my 7/70 fj40 and it has a fan clutch on the water pump. I think the oil has gone bad, due to the fact it always is spinning. Now this isn't really a huge problem except it takes longer for the engine to warm up. I have seen some threads on replacing the oil inside. But does anybody know typically what kind of oil came as a standard? Is it worth my time, or should I just buy a new clutch?

 

[bsmith123]

non clutch fan

on my 71 I went with the 7 blade fiberglass fan with a dual pulley and that worked out good for me
no clutch

I seem to remember something about a california model but I think that may have been the water pump\

Alternatively SOR or the classifieds here on MUD might help if you dont hear back on fixing it

 

[bsilva132]

It is silicone, typically 3000 or 5000 CST. Most RC hobby stores have it (used in RC car diffs) or you can get it cheap off e-bay. There are several threads on how to do it here if you search. There is a good one by Bear80 and Tools r Us has some good info as well. When you take it appart, the screws are a pain to get out with out boogering the phillips heads. I replaced the screws with hex head bolts.

Here is the link to Bear80's fan clutch rebuild:
https://forum.ih8mud.com/79-95-toyota-truck-tech/167678-fan-clutch-service.html

 

[RicardoJM]

i have a 2f in my 7/70 fj40 and it has a fan clutch on the water pump. I think the oil has gone bad, due to the fact it always is spinning. Now this isn't really a huge problem except it takes longer for the engine to warm up. I have seen some threads on replacing the oil inside. But does anybody know typically what kind of oil came as a standard? Is it worth my time, or should I just buy a new clutch?

MtnTrucker (Air Randy on Rising Sun) just replaced the oil in a fan clutch this weekend. If he sees this thread he will probably post up.

 

[bsmith123]

fan

I was surprised to learn you could actually service them
interesting even with a mechanical fan and soon a 1hdt


Cooling Fan Clutch Rehab

this is a porsche forum describing how to do it but it is interesting that they list a toyota pn for the silicone fluid

 

[bsilva132]

The Toyota stuff is expensive compared to the stuff you can get from an RC hobby store. I paid $7 for a tube of 3000 CST and had a few mLs left over.

 

[MtnTrucker]

Now this isn't really a huge problem except it takes longer for the engine to warm up.QUOTE]

Actually, if the fan clutch is bad and not spinning the fan, it should warm up quicker in the morning. You probably need a new thermostat to get faster warm-ups.

As far as repairing the fan clutch, it's really easy to do. Pull the fan clutch off the motor and remove the 8 or so phillips head screws. They're aluminum so you may need an impact hammer to break them loose without stripping the heads.

When you pull it apart be ready to drain out several ounces of really thick, sticky oil. The easiest way to get everything out is put the 2 halves open face down in a glass pan and put them in the oven set at 200*. You may need to leave them in there for several hours. Once the half with the thermostatic spring is heated to 200* look to make sure the spring is working and the valve is open.

Once the oil is totally drained from both halves, you should be able to spin the clutch hub with almost no resistance. If there is still some resistance, keep heating & draining.

I use the 10,000 cst silicon oil. It will make your fan engage more than if you used lighter oil but it will ensure cool running the summer even going up the mountain passes.

Mine came in 60 ml bottles and you use about 36 ml to fill the deep side of the clutch hub, then just put the halves together and tighten the screws good. You should feel a LOT of resistance now when you spin the hub.

I bought 2 extra bottles of oil when I mail ordered mine. If you want one for $10 I can give it to Ricardo on Wed when he comes over. Also, feel free to pull your clutch off and bring it over to the shop. I have an impact hammer for the screws.

 

[Mark W]

If the fan is locked when it should be freewheeling, the the problem is not the oil. It might be the bearing/bushing (I have never bothered to look close to see which it is).


Mark...

 

[MtnTrucker]

I think the oil has gone bad, due to the fact it always is spinning.

Wait, I went back and re-read your post after seeing Mark's comment. Are you saying the fan clutch is always freewheeling and not engaging or is it always locked up and spinning full speed all of the time? Keep in mind, unless you hold it with your gloved hand, the fan is always going to spin especially at low rpm. If it is disengaged and as you rev the engine up the fan will only spin at 20-30% of the engine rpm.

If it is locked up full time then as Mark says you probably have a frozen bearing, best to just get a new clutch. If it is free wheeling all of the time then an oil update will probably fix it as long as the thermostatic spring & valve are working.

 

[Spike Strip]

Here's a write-up from the 60 section:

https://forum.ih8mud.com/60-series-wagons/359029-fan-clutch-question.html

 

[Bigcity25]

Well, the fan spins with some resistance when the engine is off. Feels like thick syrup, can't hear any noise coming from it. I haven't tried the gloved hand trick yet but will give it a go.

 

[Mark W]

Okay... the fan is not locked up...


It is supposed to spin all the time... it just spins at much less than belt speed when the clutch is not engaged... the resistance of the air slows it and it is mainly freewheeling. It never simply sits without moving.

Sounds to me like there is nothing wrong with it, just misperceptions of what it is supposed to be doing.


Mark...

 

[Bigcity25]

Well than that might answer my question. Still might replace the silicone, but we'll see how ambitious I can get. Thanks for all the info

 

[sggoat]

Thoise clutches usually had silicon oil in them

 

[Cruiser804]

Search for blue fan clutch mod in the 80's section. He talks about the type of oil used. I doubt the design changed very much over the years. IIRC LandTank will rehab it for you for 40.00 plus shipping.

I just installed a Japanese after market on my 79. So far so good.

 

[cdtb]

When removing the fan clutch are you able to do that by removing the 4 bolts on the pulley and then sliding it past the radiator? Or does the radiator have to be removed to get at the clutch fan? Thanks

 

[Tools R Us]

Search for blue fan clutch mod in the 80's section. He talks about the type of oil used. I doubt the design changed very much over the years.

The design has significantly changed over the years. There are 3 significantly different designs on just the FZJ80, requiring different viscosity fluids to achieve the same result. The amount of shearing area determines the viscosity needed to make the intended power.

For the F motors: The early clutches are a simple design, the red hub Aisin/dealer replacement is in this category. They have a small shearing area, requiring thick fluid to get performance. Have never been able to get them where we would prefer for our climate for the FJ60/62 work just OK on the FJ40. My favorite for the F motors is the aqua hub Aisin from the FJ80, big shearing area, so strong performer right out of the box.

IIRC LandTank will rehab it for you for 40.00 plus shipping.

IIRC he only has experience with the blue hub FZJ80 clutch.

I just installed a Japanese after market on my 79. So far so good.

In my experience, all of the aftermarket ones that we have tried have had short life and/or poor performance. The Aisin clutches are far better quality and available at good prices on Amazon, so don't see the need?

 

[cdtb]

The clutch fan is on a 78 FJ40 with original 2F motor

 

[cdtb]

My plan was to remove it drain it refill it with new fluid and hope for the best

 

[sggoat]

You can get some pure silicon oil from a used network printer. Most of these(like Canon) used a silicon oil lube for the rollers and such. They usu came in containers that had ~ 1 cup of oil in them.(BTW--this stuff works great to preserve the rubber on the window glass)