viscus fan testing

Been down that track.... very simple really.
If it's hot, and if your donk is hot, then when you rev the engine the fan should "roar".
If it's not "roaring" then it's probably not working.
(you probably hear it "roar" when you first start from cold in the morning for a short time.- it should make that same noise when it cuts in when HOT.)
Cheers

Simon, should be a slight/mild amount of resistance when turning it by hand (with engine off). If there is no resistance or a heap of resistance than it probably needs looking at. Look for signs of fliud leak around the hub too, good indication that it might be stuffed.
Cheers,
Hughesy

In the end there is no real way of knowing. My hilux was getting hot under extreme load at slow speed and Several mechanics said the hub seemed fine. I stripped the hub and cleaned it and toyota sold me the correct silicone oil for $10 a vial. I put three vials in it from completely dry and for two years now the temp dont budge.

Things are not always as they seem

Discount all the other possibilities and if you are still drawing blanks do the reco.

And don't take it to your local Toyo dealer either ... they have no way of knowing.. I can tell you having been ripped off by the dealer on south coast of Victoria..

thanks guys

i tracked it down through toyota is $11 a vial