Early last week we had a couple days of hot for us weather, and the A/C in the truck wasn't blowing cold at idle as well as idle temps were creeping up. Didn't take long to realize the fan clutch was free wheeling. Long story short, between last week and today I have installed a total of 4 defective out of the box fan clutches and one good one. Murray, carquest, NAPA, 4 seasons, and possibly Duralast all of the fan clutch varieties available locally are re-branded Hayden fan clutches. Hayden has moved production to Korea and while there are good parts coming out of Korea Hayden isn't one of them. I don't know if they are getting the kinks worked out or, I got lucky and got into a bad batch, but 3 of my clutches were stuck locked, and one freewheeled. All were severe duty fan clutches. No way would a standard be able to keep up on a hot day with truck, trailer on secondary roads in hot weather with the A/C running, so I did not try a standard. I finally ordered a A/C Delco unit yesterday and had it overnighted, to the tune of $180. 3 times the cost of the other units, but it is stamped made in USA on the head of it and get this it works correctly! I'm willing to bet with Hayden they'll get this corrected, but just thought you'd all want to know my recent experience. Which is to bad, back in the day Hayden was my go to fan clutch brand.