Fan clutch Hayden 2747 vs Mopar 4095704

Hayden used to make 3 clutch types: std, heavy duty & severe duty. The HD & SD 'switch on' are thermally controlled via the bimetal coil spring in front. If one clutch turns more easily, then it is is likely to slip more....& pull less air.

The 'switch on' is controlled by the spring. The cut in temp is usually too high for my liking, so I modify the spring stop so that the clutch engages at a lower temp.