Outer Limits 4x4 Board

Ok I sort of understand how they work, as the oil in them heats up a bigger resistance is created as the oil thickens inside. I was told that the fan should be stiff to move when the engine is hot. But how stiff is that? I run the mav up to operating temp just below half on the temp gauge then shut the engine off and it moves fairly freely, am I up for a new viscous hub for the fan?

Is your engine running hotter than normal during high load/low speed situations or whilst sitting in traffic? If so, yes your viscous fan is possibly the problem. You should hear it start to roar and pull air when engine temp is getting up.

Had same prob with my 89 mav td42, and many other vehicles. Usually over time silcone fluid weeps out through seals in hub, reducing its effectiveness(less fluid=less drive to fan). Cheap solution is go to toyota (yes i know i said the "T" word) and buy silicone fluid, comes in a about a 10ml tube. You will usually need 2 to repack a hub(about $10 per tube).

To repack just remove fan and hub from engine, separate fan from hub and then undo four bolts that hold two halves of hub together. Working with rear half, turn shaft around in hub until you can see channels lining up then just squeeze in fluid. Keep turning shaft around to help fluid work in. Once channels are full, reassemble. Also have a good look at your fan blades as they have a habbit of cracking(can buy aftermarket for approx. $80).

Good luck

Tom

PS if u would like the toyata part no. just let me know and ill look it up at work.

aas said above about the silicone fluid in the viscus hub, only the diesel versions can be rebuilt, the petrol versions cant,

thanks for the tip. yeah i noticed that on the weekend while i was driving on the beach the temp was getting a bit high when it was at high revs for some time. didn't hear any rushing air noise as you describe. Got quoted $286 from repco for a new hub so you just saved me a lot of cash. Cheers. That part number would be great if you could get it for me.

Too easy, I'll look it up tomorrow.

Toyota P/N 08816-03001 some yota dealers will say they dont know about it...

would this help?
http://www.off-road.com/~estegall/tech/ ... lutch.html

And if that doesnt work, off to the wreckers and get a VL Commodore hub cause its the same as a td42 one.

Thanks for all that info. Looks easy enough, I'll let you know how it goes.