Fan Clutch Service (1 Viewer)

[Tools R Us]

I finally pulled off the fan clutch off my 1985 22R Pickup for service/rebuild. I was experiencing a slow rise in temperature at idle and determined that the fan clutch maybe the source of my problem.

Please see picture. I think the one I have is a replacement one and not the original OEM AISIN one. Am I correct?

If that is the case, is it worth servicing/rebuilding it or should I just get a OEM replacement? I read somewhere that the non-OEM replacement ones are not very good and perhaps that is why this one, if it is a replacement one, has already gave out.

Let me know what you guys think. Thanks for your help

That looks like a Hayden/Imperial clutch. IMHO much lessor quality than the Aisin clutch, I wouldn't waste time on it. They have less shearing area, so no idea where to start with the fluid viscosity on one.

Some pix of what they look like inside;
IH8MUD Forums - View Single Post - Factory fan clutch fluid replacement, still won't engage

 

[Tight White Cruiser]

Cool...thanks. Looks like I will be getting a AISIN fan clutch.

 

[FirstToy]

If the clutch is good or new and you want to improve it's performance, simply adding thicker fluid to the factory fill works well. On the new 80 series clutches I add ~20 ml of 30,000 cst to the factory fill greatly increasing performance.

Tools,
does this mean adding 20ml of 30k without draining any fluid?

just open, add 20ml and close it back up?

thanks Bear80 for the nice writeup.

 

[Tools R Us]

Tools,
does this mean adding 20ml of 30k without draining any fluid?

just open, add 20ml and close it back up?

thanks Bear80 for the nice writeup.

Yes, adds good performance over stock, but hasn't proven to be enough for AZ desert conditions, so now we change it out for thicker. Depending on use/conditions may work well for some/most?

 

[lilfoot]

this is old but i am doing this now to see how good it works on my 86 runner.i am putting 7000 in mine being i live i florida.if it does work then its a well spent $8.95 .

 

[lilfoot]

well i filled up the 3 holes and then put a little extra in the grove by the holes.it worked for about 2 minutes the went back like it was.i shut the truck off and the fan spun a good 3 seconds after then slowed to a stop.oh well i guess it'll be down til next payday and i'll buy a clutch for it.

 

[TheMAN]

somebody posted this on the *other* forum:
Fan Clutch Fluid Replacement

it has part numbers for the Toyota fluid... this is good news for those of us who don't want to go through the trouble of finding a RC hobby shop!

Here's the part numbers for reference in case that page gets lost in the abyss:
08816-03001 = 3000 cSt
08816-06001 = 6000 cSt
08816-10001 = 10000 cSt

I tried seeing if there are any other viscosties by brute force method... entering "-04001", "-05001", etc into an website ordering system... didn't work... so I think those are what's available

 

[HGiles]

Seems to me heating the cluth would make the fluid thicker and less likely to run out. Isn't that why the fluid is in there -- so that it thickens up with heat and activates the fan.

Forgive me if my ignorant newbie-ness is showing...

 

[Tools R Us]

Seems to me heating the cluth would make the fluid thicker and less likely to run out. Isn't that why the fluid is in there -- so that it thickens up with heat and activates the fan.

Forgive me if my ignorant newbie-ness is showing...

The fluid becomes thinner with heat. The torque is transferred by the unique non-newtonian shearing characteristic of the silicone fluid.

 

[Bogo]

I think this is the style Toyota uses. I'd have to dissect a Toyota one to be sure. I've pulled apart other manufacturers ones and Toyota's looked similar to the them. There is a simple pump, reservoir, valve, and sheer plate pair in the fan clutch. The pump is formed from the shape of the driven disc in the middle of the clutch, and outer casing. When the disc in the middle of the clutch rotates, the pump continuously pumps the silicon oil into a reservoir. It will quickly pump all of it into the reservoir. As the little coil on the front of the fan clutch heats up, it opens the valve which allows the oil to flow out of the reservoir and onto the sheer plate pair. One half it is a portion of the disc, and the other is a portion of the outer casing. The shear force in the silicon oil transfers some of the rotation from the disc to the outer casing which the fan is attached to.

The higher the ambient temperature at the coil on the fan clutch --> the larger the valve opening --> more silicon oil circulates --> less clutch slip --> greater the force driving the fan --> faster the fan spins --> more air moved. It never fully locks up. If it did the pump couldn't move oil back into the reservoir, and it would permanently lockup.

The fan clutch has all those fins to dissipate the heat built up from all the friction in the silicon oil. They use silicon oil because it is durable and maintains its viscosity over a very long time under stressful conditions.

 

[Tools R Us]

^^^ Correct except:

... They use silicon oil because it is durable and maintains its viscosity over a very long time under stressful conditions.

Should read:
They use silicone oil because of the unique non-newtonian shearing characteristic of the silicone fluid.

This is what provides the fan drive, try any other type of common oil and zero clutch engagement.

 

[arndog123]

Bringing an old thread back up. I'm doing a fluid replacement and forgot to make match marks before pulling the fan clutch apart. Does it matter if I don't mate the two parts exactly how I pulled 'em apart? I'm hoping no.;p

 

[Bogo]

I never bothered.

 

[buschmaster86]

I one looses the rubber o ring..can one just take universal liquid gasket to replace it ?

 

[Pacer]

I one looses the rubber o ring..can one just take universal liquid gasket to replace it ?

I would not in this case. This is a flange meeting an o-ring seal, not surface to surface like a timing case or oil pan...


Another note on this topic that I have not seen mentioned. If your fan clutch is soaked and covered in black dust/oily mess, the seal around the shaft has gone bad and new new oil will just leak out and make more of a mess. Scrap it and replace unless someone here has a method for replacing that seal too...

 

[Bogo]

On one where I had an oily mess, I cleaned it up real well, used the old seal, but potted both sides in Toyota FIPG gasket. After a couple years it hasn't leaked yet. I used a very thin bead if the FIPG. In tital it was maybe about the volume of the original gasket. I didn't want any squeezing to the inside and gumming up the fan clutch.

 

[Pacer]

On one where I had an oily mess, I cleaned it up real well, used the old seal, but potted both sides in Toyota FIPG gasket. After a couple years it hasn't leaked yet. I used a very thin bead if the FIPG. In tital it was maybe about the volume of the original gasket. I didn't want any squeezing to the inside and gumming up the fan clutch.

Good to know Bogo, thanks for the follow up.

 

[brakasha]

I believe you can just squirt some RTV blue in the gasket groove and pack the gasket in there tight. Make sure not to put too much in, as it can spill over the ridge separating the outer ring and inner fan clutch and cause it to bind up, causing the fan to spin at the same RPMs as the engine (can cause everything from just an annoying noise to failure of the water pump). Should work fine.

 

[greggyb]

I have a 1986 pickup with a 22r motor. I didn't realize that the fluid has been leaking out of the fan clutch for a couple of weeks, and today I discovered that when the motor is running I can stop the fan. Is the clutch worth refilling or do you think or should I get a new one. I'm really low on cash right now.

 

[flash02]

I have a 1986 pickup with a 22r motor. I didn't realize that the fluid has been leaking out of the fan clutch for a couple of weeks, and today I discovered that when the motor is running I can stop the fan. Is the clutch worth refilling or do you think or should I get a new one. I'm really low on cash right now.

What's your time worth to you, from what I have read to service the fan clutch properly takes some time, it's not as fast as changing the engine oil. I luckily had a good clutch laying around and just swapped it out. Check around you may be able to pick up a new clutch for around $60.00.

For the record you will be able to stop a viscous coupled fan when the engine is running. A good why to check the condition of the clutch is to spin the fan when cold, there should be a decent amount of resistance, if there is little to no resistance the fluid is gone or lost its viscosity and ability to do its job.