Topic: FAN CLUTCH

[UGLYTOY]

there's an old thread that mike (i think) put in the part number for the fan clutch fluid.  it doesn't say why u were replacing it......mine has no signs of leaks, but at trail speeds under a small load (not honing on it, although this will heat it up also), it's getting close to the red.  i took an old one apart that had similar symptoms, but was worse about heating up (that truck got fixed w/an electric fan from a tempo);  that clutch had no signs of leaks, it had fluid, didn't seem like a whole lot, but not sure how much they should have.  i looked at the back side of the spring and don't see where it engages anything when it moves.....is there supposed to be something there that may have broken off on mine internally?   i didn't see any pieces floating around, but maybe they ended up under the gear.  i had another clutch that i put a propane torch on briefly--it looked the the spring wound a little tighter, but the fan wasn't really any harder to turn......what am i missing (that clutch may not have been any good either, i never ran it)? 
in case u r wondering, the rad is clean in the fins, but if u put your hand in front of the rad, u can't feel air sucking through it like other vehicles, but on the engine side, there is air movement--no, there are no broken blades either and the shroud is on......i'm thinking the clutch is allowing too much slippage, but am not convinced the oil will fix it since i'm not seeing any leaks + the fact that when it's cold, the fan does roar like it should (meaning there is some oil in there....)
again, it's just a low speed thing, it's a problem that's quickly getting worse and nothing new is blocking the rad since it's been getting worse (winch, etc).....any ideas on what i'm looking for w/the clutch apart?
i don't really want to do an electric fan again simply because this truck has a winch
thought i'd ask here since some have had them apart

[79coyotefrg]

the fluid in the clutch  gets thick and sticky when i t gets hot,  not sure what it is,  but it kinda  evaporates over time, 

i put some 90wt in one  but it doesnt help    but it was just a test   im going with a electric fan i guess  

[UGLYTOY [OP]]

what's in there is thicker than gear oil, which is probably why your experiment didn't work (i thought about they same thing until i tried to pour some on my finger--it takes forever to pour and nearly feels like grease--it's supposed to have a high viscosity number)
i wondered about the evaporation, but regular oil doesn't evap out of a diff or engine and besides, since seals in good shape (not leaking), not sure how it could evap.....on the other hand, i'm not convinced there's enough oil in it....if mike or someone else that has put oil in theirs doesn't answer in a few days about why they added (leak or problem like mine), maybe i'll break down and buy some of the factory stuff and see what happens.....it's less than $10
thanx for the reply

[Ramrod]

why not just get a new fan clutch? 

[UGLYTOY [OP]]

because i'm too cheap....i like to waste twice as much $$ up front trying to fix something that would be better off just replacing in the long run.....besides that, i am curious why mike, marlin and whoever else was adding fluid to theirs (the thread didn't say)--it's probably best just to replace the clutch....since i'm not convinced the oil is the problem, that leaves the spring, which doesn't seem to be replaceable that i know of

[Willy Mammoth]

The oil is a silacone and is thick enough to cause resistance between the internal parts of the fan clutch causing it to spin the fan. It can still be slowed down compaired to engine speed so it don't spin too fast at high rpm. The looser the clutch the better the mileage, the tighter the clutch the worse the milage and noise factor.

We used to pack the Nissan clutches with STP and that worked ok, but you can't go wrong with the factory stuff.

[toyfamily]

I just rebuilt my clutch fan on a 90 4-runner. I threw away the empty tubes of oil so I can't get you the p/n. Just ask your toyota parts dept--that's what I did---and they knew what I wanted along with the P/N.

Mine took 2 tubes to fill completely and it solved my issues where the radiator would gurgle and boil over when shut off.

[kneedownnate]

If I remember right it's almost $10 a bottle, and you need a little more than one if it's dry?  The dealer will know the part #, and if they don't they're a moron!  Wait, I have an empty bottle floating around here somewhere..............
can't find it now, but I will when I'm not looking!  I'm gonna try stp also, but I usually have a couple of spares around.

[UGLYTOY [OP]]

an old thread has this part number:    08816-03001
no one on that thread or this one so far has said why they are adding the fluid.....are you guys seeing leaks, or just having problems similar to mine?  if it's a similar problem, does it fix the problem and does it seem to rob any engine power (not sure if u guys may be overfilling the clutch putting 2 packs in....?)

[Willy Mammoth]

If you here a loud wherrring noise and the fan does not slow down at high engine rev then it is too tight.

[kneedownnate]

You put it in till it's full, and if it only takes one tube then great, but if you're having problems it's probably going to take 2.  I put it in because there wasn't enough resistance and the fan would freewheel too easily.  With engine off, if you grab the fan and try spinning it, it should barely turn before coming to a stop.  If you do this and it just keeps spinning you need fluid.  Pretty simple really, fluid offers resistance.  If this doesn't solve your problem then you have a cooling system problem and need to get it fixed.

[RustyToy]

would this solve a problem of overheating on the freeway?  new rad, new motor, new thermostat.

[79coyotefrg]

should, i always get a thermostat with a bleeder for air  or drill a couple holes in the outer part to let the air and water to bypass some

[kneedownnate]

If you're overheating on the freeway but not around town it's more likely your radiator being plugged.  Best way to tell is disconnect it, run a garden hose full bore in the inlet and feel for spots that aren't cold like the rest.  Guarentee you probably have a blocked off section.