Exactly the same except the friction clutches on the big trucks will sometimes give a shrill shriek when they first lock up.

 

yeah, my ol granite had a high picthed "belt slip" when it cranked up the fan. far as i can tell, i dont ever hear that sound or anything like it on this thing

 

It is funny we have problems with our fan not locking up and there is a member on another forum just ordered a new fan clutch because he doesn't like the noise when his fan comes on.

 

Clutch Fan Test

-Enjoy
fh : )_~

 

after doing that test. my engine was still at 180ish to begin with... when i revved it up at first, i heard the fan spinning up with the motor, and within a few seconds it kicked out... put the cardboard behind it and it got up to about 225-230 when i shut it off. the only time i could actually hear the fan was when i would let the motor go back to idle then bring it back up it would roar for a ew seconds and then get quiet...

when i shut it off at the 230 mark and took out the card board it would spin the distance of one blade when i flipped my wrist. cranked it back up with the same fan results, hear it when the motor revved up and then went away shortly.

with the truck temp still between 212 and 220ish and off the fan would flip 2 blades by using my finger to push it with a flip of the wrist...

does not seem to good to me???

also, while holding the idle up and engauging the ac compressor it would bring the truck back down to about 800 rpm... is this normal??? turn comp off and ater a few seconds it would pick the motor back up...

 

The fan clutch locked when the engine is first started is normal, the fluid is not distributed evenly in the clutch yet.

However it sounds like the valve that locks the clutch is not working as it should.

AC compressor is a good drain on engine power when it kicks on.

 

does that mean it needs ro be replaced? the price scares me