Fan Hub Question

[m38inmaine]

I have the cooling system apart for a water pump replacement and I noticed that the fan hub, the part that has the quick disconnect fitting, does not rotate freely, it turns about half a turn and then feels like it has hit a spring detent then will rotate again to another or the same detent, is this normal not to spin around freely ?

Thanks

 

[Mogman]

I looked at one in the shop and it turns smoothly and continuously, in fact it has to as the rest of the ass turns while the little hub on the front is stationary.