[cpfullback]

Just got back from a fishing trip, towing up and down the sierra mountains. Noticed when the fan clutch engaged I would get the normal loud whoosh of the fan and it would cycle on and off. The thing which caught my ear was when the fan clutch disengaged there was a metallic-whine which would last a few seconds and then go away. That seemed to happen each time the fan clutch locked and unlocked. Could that be a bearing in the fan clutch going bad? The noise does not happen at any other time, just when the clutch unlocks the fan.
Thanks

 

[ZMANN]

that sound is common on the 6.o water pump pulley to belt screech it sounds just like metal

the fix is to sand the WP pulley
I know the 7.3 is not the exact same pulley but I was so sure my fan clutch was going out i was ready to replace before I read this http://www.bulletproofdiesel.tv/Files/Documents/Fan Clutch Adapter Tech Tip.pdf
it seems worth a try to inspect your pulleys first

if nothing else BUMP lol