How to re-co a clutch/viscous fan hub (RD2.8T)

[krbrooking]

So firstly some info about how they work.

This is a Quote from [The Evil Twin] in another thread:

The clutch works by porting fluid using a thermal spring to increase or decrease drag.
The more fluid on the clutch side the more friction to drive to the fan
The less fluid on the clutch side the less drive to the fan
With the porting all the way open IE fan clutch bimetallic spring sensing above about 80 degrees the fan should spin at better than 50% of the belt driven coupler.
That varies in the rating of the cluth tho, some may be as high as 85%.

Things are a little different on start up initially but that isn't a biggee

A viscous coupled fan has two disadvantages.
One, it loses efficiency if there is insufficient fluid to port to the clutch side, and two, it works off the temperature of the coupling not the temperature of the engine/engine coolant IE it relies on convected and/or radiated heat to decide how much air it pumps.

And this was A link from [FNQGU] from the same thread: http://neuralfibre.com/paul/4wd/tuning-and-understanding-your-toyota-viscous-fan-clutch

So after reading through them I went ahead and cleaned out and refilled my viscous fan hub.

[krbrooking]

Here is what I used thanks to [Mudrunnertd]:

Toyota genuine part
Oil, Silicon
P/No 08816-10001
Loc No. M1-11-03-3C
18ml tube

56897 56898


They cost $11.10 per bottle, I bought 2 and used both.

[krbrooking]

So now on to the process:

Firstly remove the fan assembly from the car by removing the shroud then the 4 bolts holding the fan hub to the pulley.You should now have this:

56899

You then undo the 4 bolts holdout the fan on and the 4 bolts holding the hub assembly together:

56900 56902 56901 56903 56904

Now the fun begins, the silicone oil inside is very tacky and thick it takes a while to clean and drain out. It took me around 1.5rhs as I used some fuel with a paint brush and spread the fuel around then let it sit on an angle for around 5min for it to drain a bit. Then repeated the process over and over until I was satisfied it was completely clean. I then re-filled it with the new tubes.

The clean product.

56905

The full product.

56906


You can tell in this pic that there is some fluid on the bottom of the centre bit. I pushed that black bit (spring loaded) on the bottom left down with the nozzle to fill it, once the front section was full it obviously overflowed into where you can see it now.

You now reverse all the steps above to replace the unit. I would like to thank the ppl mentioned in above posts and Parksey as he has assisted me via PM's as well.

I am also not 100% confident/sure it is full enough, as you can see by the above pic that it does not look like much in there, but I have put it back together to see how it would work and go from there.You might also choose to replace the "o" ring on the outside. I did not as mine was fine, so i am not able to help with any info regarding it.

[Sir Roofy]

Good job Kev let us know if all is ok