Hi,

As most of you may be aware, I have been doing a lot of research lately on our cooling system in the 80's including the fact that we have a dead spot on the OEM temp gauge which prompted me to not rely on that in terms of deciding if my cooling system was still healthy.

As a result of knowing that there is a Pesky heater host at the back of the motor that goes and causes a lot of overheating problems that sometime result in head gaskets and major engine repairs, I had all of my heater hoses replaced - I mean after 14 years of a well maintained car - they can not and don't last for ever. I also had my Fan Clutch replaced as Preventative Maintenance at the same time(135,000K's) because they apparently are shot by 160,000k's. Fan clutches apparently don't generally just stop working - they work less and less efficiently over time, then with the temp guage deadspot, you don't notice it until it is that inefficient that the deadspot on our temp gauge is overcome by extreme heat.

I also had my radiator looked at, it was still the original OEM which is Brass Core with Plastic tanks - it has signs that the radiator tanks could give up soon, so I ended up having it replaced with a Brass Core with Brass tanks - this should last even longer *fingers crossed*

Then after all of this, I decided to overcome the temp gauge dead spot by installing one of these temp gauges - Click here for info on the Digital Temp Gauge with ALARM - which then caused me a little concern as my temps were 5-6 degree's higher than other friends and people with the same car.

As a result of further research, I found out that the NEW Toyota Blue Fan Clutch which I had, was found to be set differently from one unit to the other and that they also had different amounts of oil.

There is hence three things you can do - add oil, adjust the temp that the clutch begins to engage, or do both.

I have only added and removed oil - which seems to have solved my problems - it definitely has brought the temps down to where it should be and it is definitely behaving the way it should be - ie. engaging at higher temps and cooling the engine better when the engine revs are raised - it wasn't doing that from new. I am still doing testing however - need to test it owing my 2.5T boat. Towing a Jetski, it tests okay so far.

The Genuine Toyota Blue Fan Clutch is one of the very few that is ADJUSTABLE - however the original one, I am advised can be toped up with oil no problems.

Now, I had a mechanic remove and top my fan clutch up with 2 Tubes of oil from Toyota - this is what Toyota advise people to do.

When I got it back, I found the temps had come down but the fan seemed engaged a LOT - I am judging this by the noise it was making.

As I have had the car from new, and I have never heard, nor do I recall the fan being that loud, I decided that as these clutches are coming with differing amounts of oil and settings, to remove ONE TUBE of oil - ie. 18 mils. This means I effectively have added ONE TUBE of oil to my fan clutch from the factory amount.

I did this using a syringe.

This for me seems to be perfect right now - I want to test it towing a 2.5T boat - then I will say that for me - one tube was perfect or not.

I will also add that when adjusting the clutch timing which I will detail how to do below - there is a way to put what has been determined the correct amount of oil - I am not sure where this is in relation to my clutch because it requires you to leave your clutch overnight to drain the oil which I didn't have time to do. From the research I have read, one tube seems to be what it takes to get it to the correct level.

Here is the instructions on how to top up the oil and do the mod in regards to adjusting the temp which the clutch locks up.

READ THE WHOLE THING BEFORE ATTEMPTING THIS.

To do this, you will require the following tools

One or Two-Three Tubes(TWO or possibly Three Tubes(Third Tube just in case) if you are doing a full empty and refill, start with ONE if you are just topping up a new clutch) of TOYOTA Fan Clutch Oil available from Toyota Dealers
Locktite 242
#3 Philips screw driver
#2 Philips screw driver or impact driver may be needed.
12mil 12pt RING SPANNER
10mil 12pt RING SPANNER
Socket wrench for undoing the Fan Shroud bolts
It is preferable to use a TORQUE WRENCH to tighten up the nuts on the Fan Clutch Hub that is suitable to 40 Nm of Torque

warning: None of the parts within the clutch are serviceable by TOYOTA. Be gentle with that O-Ring. If it appears to have stretched and there is a bubble when placed in the groove, simply start from the side opposite the bubble and work it back into place compressing it as you go.

If you are doing the adjustment of the clutch then you will need a BBQ ROAST thermometer like this one below:



First we must remove the clutch from the car.

First undo the FAN Shroud - this is the big plastic cover on the back of your radiator. This took a bit of manipulation to move it towards the engine with the top radiator hose in the way a bit.

Next, undo the 4 x 12mil bolts holding the clutch hub and fan assembly on. This can be a pain because they are TIGHT. The nuts are very SOFT - I used a 6mm FLANGE Spanner - however I recommend you use a 12pt RING spanner (DEFINITELY NOT 4pt) as they WILL BUR EASILY. 2 of mine were already burred by someone previously so I am going to replace them this week.

Lift the Fan and clutch assembly carefully out - you may have to manipulate the fan shroud a bit so you don't damage the radiator fins with the fan assembly.

It will look like this:



Once it is out of the vehicle, now remove the 4 FAN nuts so that the FAN and Clutch can be separated - These nuts are ALSO VERY SOFT - again - 12pt 10mm ring spanner is a must in my opinion - they are also very tight.

If you need to get replacement NUTS - the thread sizes you need are 8 x 1.25 mm and 6 x 1.00 mm, the Toyota nuts are flange type in both applications.

Now that your fan is off the clutch, it should look something like this:



Here it is with FAN removed and the hub side facing up



Here is it with FAN removed and the hub facing downwards - this is the side that faces the radiator - the thermo you can see there is what senses the temps from the radiator and progressively locks and unlocks the clutch.



Before disassembly of the clutch, clean the outside of the clutch completely so no debris will enter it upon opening it up

Now you need to REMOVE those 8 screws above so that we can separate the two halves of the clutch.

Again - these SCREWS like the previous nuts are SOFT - make sure you pick the right sized Phillips head screw driver for the job and take your time. Some people have totally burred screws and had to resort to dremel tools etc. to get them out - mine were fine though - keeping in mind that mine was brand new and had already been apart once before. Some people recommend using an IMPACT driver to get them off if the clutch has been on the car for a long time.

To do this I placed my clutch assemble on a Vice carefully not to damage the fins on the clutch - YOU MUST HAVE IT LEVEL when you do this, or oil may spill out.

Once these screws are removed, you can then carefully separate the two halves but before hand, you will notice a slight vaccumm as you slide them apart, you should have the Thermo sensor shown in the previous pics facing DOWN which means you flip the clutch over after you remove the screws before actually pulling it apart. This is the side that contains most of the oil from what I found.

It will look like this:



Here are some close ups of each side once opened up.

This is the side I top up and remove oil from which has the reservoir which has the thermo sensor facing downward.



Here is the other side which has the hub side facing downward.



Now, it's time to ADD oil.

I recommend first trying adding ONE TUBE - this seems at this point in time, just right for me. If after towing I find different in the next week or so, I will edit this.

Some people recommend when doing the Adjustment of this clutch, that the oil level is filled after ALL oil is drained out over night (to drain ALL of the oil as it is very thick) and that two full tubes from an EMPTY CLUTCH will bring it up so that the oil is level with the bottom of those holes you see in the pic below



I believe two tubes to be accurate because Toyota say - if your clutch has leaked all of your oil out, then to add two full tubes.

Ths means you have to put the clutch HUB side down overnight BEFORE SEPERATING BOTH HALVES, then put that Half in a container after separating the halves for another overnight stint to drain it all out.

Some people say that placing the parts on rack of some sort with a catch pan and put in an oven at say 150 degree's F goes along way in getting that stuff to drain more completely out of the base since that side doesn't come apart is a faster way than waiting over night....

I didn't have 24 hours to wait before needing the car, so I effectively added one tube to the factory fill as my mechanic had not drained it overnight either when he added two tubes so there was probably 18 mils(one tube roughly) in there already when he added two tubes. What I did - was use a small syringe to remove exactly 18 mils. I am telling you this, so if anyone overfills and it locks up too much, this is how to accurately remove one tube or whatever you want.

Then we need to re-assemble if you are not modifying the clutch timing.

Now replace the top of the clutch and tighten down the screws. If the O-Ring has come out of it's groove you'll need to work it back into place. The easiest thing I've come up with is to start from the opposite side and work it in by compressing it together. Once it's in place it will stay there during reassembly.

The torque spec that I've come up with for those screws is: Good and tight - being careful NOT to BURR the screws - remember to use Loctit 242 - now you need to put the fan on and install it back into the car.

To do this, do everything in reverse using locktite 242(according to the FSM) on all bolts and screws. Again - use a 12pt ring spanner on the nuts!

When putting the fan and clutch assembly on the hub, the FSM states to do them up to 40 Nm of torque.

Now, if you want to go one step further and modify the timing as this is ALSO APPARENTLY DIFFERENT ON EACH CLUTCH - apparently, they engage at anywhere between 105 degree's F to 125 degree's F. The ideal temp is apparently 95 degrees F. Apparently only onein 8 brand new clutches opened up were set correctly at 95 degrees F.

The modification involves, a few additional steps... first involved sitting the clutch whilst both halves are still together before removing the 8 screws overnight with the HUB side down to ensure all oil goes into the oil reseviour and then after you remove all 8 screws, and Adjust the Clutch, Remove all oil by sitting both halves upside down in a container overnight so it can ALL pour out - we will get to that after we adjust the timing.

Now, put the half of the clutch which has the thermo sensor on it into a frying pan with the thermo side down in water(1.25 inches of water in a sauce pan to make sure just the thermo sensor is completely covered but not allow water to bubble into the inside of the clutch) and heating it on a stove until it gets to 110 degree's F using a thermometer like the one pictured below.



Once it hits 110 degree's F, place the pan with the clutch in it on a wooden board which helps slow the process of cooling down. Since the pan with water in it will cool at the edges faster than the center where the spring is at, it's important to occasionally lift the clutch up and down to help circulate the water and minimize that effect do this every few minutes and then more fequent when you get closer to the target temp of 95 degree's F.

Here's a pic :



Loosen those two screws and adjust it so that when you look straight down and the TEMP on your thermometer is at 95 degrees F, the two ROUND holes are half closed and then tighten up the two screws - Let me explain...

You'll need to sight threw one of the small round holes and adjust the plates position so that half the hole is open and the other half is blocked by the valve.

If the holes don't align perfectly to each other one should be 50% open and the other should be more than 50% open.

This must be set when the temp is 95 degree's F.



Personally, after this was set, I would heat it up again, remove the clutch from the pan and wait for it to come down to 95 degree's F and make sure it is set correctly. I would also out of my own curiosity have heated it up to say 125 degree's F and taken note what temp it was originally set at - so if I wanted to go back - I would know where to go.

Now remove all oil by sitting both halves upside down in a container overnight so it can ALL pour out. This will take a few hours minimum, overnight would be best.

Once the clutch is empty, fill the HUB to the underside of the drive plate. Looking through the holes in the plate you'll see some rectangular reliefs that will help you in determining when you've reached the underside of the drive plate. Empty both tubes completely into the clutch and it should be the right level.

You'll want to add oil to all the holes as this stuff is pretty thick and doesn't flow easily.

Now you can reassemble as per above.

At this stage, I have not needed to adjust the temp that it kicks in. I will see what happens when I tow a 2.5T boat on a hot day - hopefully weather will permit this week end.

Keep in mind that to make sure that your temp are correct, you really need to have an accurate temp gauge on your cooling system to be able to see BEFORE and AFTER results - as the OEM gauge will hide any irregularities if your temp is not up near boiling point but well and truly out of the normal range - therefore I recommend you install either a mechanical type gauge in your top radiator hose or a lower cost, easier to install and just as accurate one of these which also has the added benefit of an audible alarm which you can set if the temps go out of the normal operating zone before your OWM gauge starts to move giving you more warning to take action should something in the cooling system fail. - Click here for info on the Digital Temp Gauge with ALARM

Just realised that I never followed up on this post of mine.

The results were great - The engine temps are now stable when towing as well as driving around town...

If you are having issues like I was - I reccomend at least replacing the oil with the correct amount and then if you are not happy, checking the adjustment as well.

Hey Frank do you still have the part number for this "Blue Clutch"? Is this the only clutch that is adjustable? Are the stock ones not adjustable? I was at toyota last friday and asked them about this blue clutch and they had no idea. I have the 4.2 Factory Turbo. My Auto meter Temp gauge goes all over the shop, always comes back to 180Deg F but when towing the box trailer (450Kg + 9 Play Tyres) on the freeway, its not un usual for it to randomly go up to 190 Deg F and if i work it hard it will go to 195Deg F but will never go higher. So i think its deffinately that cheap shit Repco fan clutch! So before i go to fraser in Jan im going to get the block and Rad professionally flushed new thermostat and a genuine Toyota Fan Clutch.

Troy

I just went into toyota and ordered a fan hub (for a petrol, they said diesel was different) and when it turned up it was blue.
For $500 it would want to be good.

So is that new one for your multi-valve cruiser? Is that to suit a petrol or did you order the different one for your diesel???

Troy

No, I had to get a new one for my petrol cruiser. With the old one on the right I could stick my hand in and stop it anytime* and there was no way to add oil to it. Dunno what brand it was but it had made in USA on it.

*do not try this yourself, I'm a trained idiot.

Hi troy,

I have a 1HZ diesel and have been having major over heating issues for some time with varying factors. My fan clutch is genuine 2 months old (they are not cheap!)
Part code: 1621017021
Not sure if blue fan can be used? Mine was a warranty claim anyway

If you wish to look up yours and compare with others, such as the petrol 80s use this website. Ignore the price listings but all the part codes are still current and correct.
online-toyota-epc-t2058.html

Now I have replaced my entire cooling system in the last 6 months or so as well as adding PUSH thermo fans which do help abit. Radiator, thermostat, all hoses, fan clutch, fan blades, water pump - all genuine of course, 2 thorough radiator flushes by natrad due to mud ingress etc etc
I've been tearing my hair out every offroad occasion

As frank has detailed above our viscous couplings all come with different settings and can become a real PITA.
He is also correct in saying only the BLUE FAN clutch has those 2 adjusting screws. But you shouldn't need to go to those lengths as varying oil amounts should suffice imo.

I have just taken mine apart on the weekend and found it to have less than half the amount of oil it should have had. Adding 1 tube of 18mils only brought it to just below "those 4 holes".
I was hitting 95+degrees Celcius everyday which has dropped by ~10degrees. Fan is engaged a lot more and seems to be functioning properly now, although it could still be better so I will be adding a further 8mil or whatever is required to bring it top level with those 4 holes this weekend.

Here is a pic of mine;


The part code for the Toyota SILICON OIL (18mil tubes) is 08816-10001
I had difficulty sourcing this so hope it helps.

Note: I use the digital temp gauge (from frank) with sensor mounted on top radiator hose.
I have always used genuine toyota 76degree thermostats (not factory 89s!) but currently using aftermarket.
My temp gauge seems to sit just below half even at 85degrees, but as mentioned our factory gauge does not move until around 100degrees. By 115 it is off the dial!

I shall report back here when I make further adjustments to oil. I am wanting to reach no more than ~83 MAX flogged to it's limits running the colder thermostat.

Thanks goes to frank for this lifeline thread! I'm sure many of us would still be chasing other possible causes!
If you cannot hear your fan ROARING and are running hot I would be trying this first before anything else!

Have fun.
Cheers, Glen.

Gudday Graeme

Would you mind posting the part code for your newly purchased blue fan clutch?

Thanks.

Cheers for that fellas. i dont think the repco viscous is servicable. But i asked about one to suit a 1HDT/1HDFT and old mate said $470 Trade price. so i think i will put a genuine viscous on before i hit the sand loaded up to the hilts with the AC on

rezpkt, once you get your oil levels right will you remove the thermos.......is it possible that they are restricting the factory fan?

Let us know how you go

Troy

A couple of months ago I was about to bite the bullet and buy a new blue fan clutch from toyota as mine had kicked the bucket but was lucky to find a genuine blue one being sold on ebay which was only 9 months ago (he had a receipt to prove it). The starting bid was $0.99. Here I was putting a maxium bid in of like $400 and before I knew it I won the bid at $40!!! and with a 15minute drive to pick it up I was laughting.
Over the last couple of months I been monitoring my temperature and the higest mine has hit has been 84 degrees but on average it sits between 75 and 80 degrees. I also installed a thermo fan on the front of my radiator when I put the new fan clucth in but I have not had to use it. Ill tested it out though and while its running my temperature guage barley moves above 76 degrees. For $125 odd dollars I never plan on NOT having one again.

16210-66020 coupling assy

Hi Troy,

I have only just seen this post - sorry for the delay... I am not sure of the tempss for the diesel - but if this was a petrol - I would say those temps are normal....

some of you might find this a bit dodgy, but it crossed my mind. Whats wrong with turning the fan into a purely mechanical fan rather than relying on the viscous hub?

Ie: Drill and bolt the fan through the viscous hub permanently to the shaft on the engine side so the fan is always spinning. the thermostat remains closed until the engine reaches operating temp so that wont make a difference and that way it will only cost $5 for 4 nyloc nuts and bolts instead of $500

any reasons not to do this?

You will unneccesarily rob your engine of horsepower all the time, load it up when cold and reduce fuel economy.

Also, keep in mind engines run more efficiently when hot.

You want the engine to run at the spec temp that it is supposed to as per the engineers who designed the engine to run.

There is not a design issue here so why change the design? In my opinion, Toyota's cooling system is good. It's just a situation where the third party making the hib is giving inconsistent settings on the part that they supply and hence why they should be adjusted and set correctly when replaced.

I did this on our truck with a VT190 v8 cummins and it deffinatly robbs the power and boy did it ROAR.