fan clutch question

I have a viscious coupling fan clutch and I dont know how to tell if its ok or not. I had to replace my water pump. When I was removing the fan I grabbed a fin on the fan and wiggled it and the clutch assembly did not seem as "connected" to the pulley/pump assembly as I think it should be. No, I am not talking about the 4 bolts that bolt the fan to the pulley, those were tight during the wiggle test. Anyone?

Karl

 

any signs of leakage/dirt around the input shaft/seal area would be bad.
also, any wobble detected in that same area would suggest replacement.
Fan clutches, or Tempatrols, are sensitive to heat and react accordingly.
Most have a bi-metal spring on the front/face of the unit.
A typical unit would engage when engine is first started cold, then disengage until engine temp rises enough to cause the unit to engage. The theory is that the fan is not needed while cruising at speeds above say 35mph; air flow thru the radiator from driving speed is normally enough for adequate cooling.
In theory, with the unit disengaged, with engine cold and idling, you should be able to reach in and stop the fan blades: DO NOT ATTEMPT TO DO THIS>>>PERIOD !!!!!!!!!!!!
The unit should be freewheeling and disengaged. Although the fan blades are spinning, they turn due to centrifugal force of the water pump and pulley.
One way to check would be to cover the front grille area with fender cover, bath towels, etc to block the air flow at idle. Let the engine warm up and continue to run; engine cooling temp should increase due to the reduced air flow; the fan clutch should kick in about 210-220 on most engines; you should hear the "roar" of the fan blades when this is accomplished; if you don't hear this at idle, gently increase idle speed and the unit should engage; once again you should hear the "roar" of the blades and feel the pull of air from the fan.
if you can't get any results at all from these simple tests, replace the unit or install Fan Clutch Eliminator if you want to go to solid fan set-up.

 

Hmm, I did have the urge but stopped myself from attempting to stop the fan with my hand... Not Thanks for your description; far more detailed than the TSM. In fact, after overheating, the clutch started to engage the fan occasionally. This was one of the factors that lead to my wanting to know. Hmm, I suspect a faulty part. Now where to get one? NAPA (Never Any Parts Available) maybe?

Karl