i have a question.. when the car is off i can pop my hood and grab the fan and spin it around non-stop.. i dont think this is too right... how can i tighten it?

 

What I found:

The fan clutch is designed to provide limited fan movement when the engine does not require cooling, therefore saving fuel and reducing fan noise.

Excessive slippage. A hot engine in the ‘off’ position which allows easy, revolving manually, from 1 to 1 ½ revolutions of the fan indicates a weak fan clutch. A new fan clutch should be installed.