OK - bear with my ignorance...the FSM is mum on this.
My fan clutch apparently is engaged all of the time - at least it is when I start the engine (and the engine is obviously dead cold). My impression has always been that this is only supposed to be engaged when the engine is at certain elevated temperatures - right?
Over all of these 22 years of ownership - I've never noticed it when starting.
These are pretty pricey units - other than maybe a tad less power/MPG - any harm?
Thanks,
Tom M.

mine is usually engaged when i first start the truck then after a few seconds it disengages and acts normal...it has been doing this for over a year and havent had any overheating problems so maybe its normal.

The fan clutch is a Viscus type clutch. If you ever have one come apart then you know that there is a some silver colored nasty crap inside. What happens is over night the stuff settles down and thickens up a little. So when you fire it up in the AM. it takes a block or so to get back to it's normal operation. Don't even give it a seccond thought, unless it's on "all" the time and making lots of noise, OR it's flinging that nasty crap out of it, OR it wobbles like a homeles guy trying to stand in the middle of trafic. Other than that it's cool.

its filled with silicon oil you can buy the oil from toyota ($12.00 per 1/2 ounce takes 2 bottles) and rebuild it the oil comes in 3 dif viscositys std turbo and extreme i have a new fan clutch i could sell you

2nd that - not only the better cooling but you also get a HP gain