Water pump pulley fan clutch nut off?

2000 GMC SIERRA
325,000 MILES • 5.3L • V8 • 2WD • AUTOMATIC
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PACKERS27
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I'm having a very very hard time getting the fan clutch nut off of the pulley. Some people say that you turn it clockwise and some people say you turn it counterclockwise but the way the fan blades look, it looks like you turn it clockwise to loosen it. I cannot for the life of me loosen this nut. I cannot find a pulling range at any parts store. This pulley has four holes in it and supposedly it fits an M8 so you can use a long screwdriver or a pry bar to hold it while you try to turn the nut. I've also tried to put some heat to the nut and still didn't work. I've tapped my wrench with a hammer to try to shock it but nothing works. I even tried turning it counterclockwise and it still won't budge. I cannot hold the pulley well enough to even try to make a real effort to turn the nut. Strap wrenches doesn't work either. Well the Robert ones don't. My question is, it is reverse thread and you go clockwise to loosen it right? Also do you have any ideas on how I can get this fan clutch nut off? I'm changing the water pump
Dec 12, 2025 at 2:38 PM
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STEVE W.
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Should go counterclockwise to remove the fan. I normally use a tool that grabs 2 bolt heads and then a large wrench. The wrench gets put on and smacked with a mallet to break the threads free. They are constantly being tightened when the engine is running and they get TIGHT.
Dec 12, 2025 at 3:22 PM
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PACKERS27
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Is there a way to know for sure which way it loosens? I've smacked the wrench a few times and also put heat to it. It just doesn't budge AT ALL
Dec 12, 2025 at 5:20 PM
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STEVE W.
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Yes, it turns lefty, counterclockwise to loosen. They usually require a good hit to break them free at the best of times, they do use blue loctite on them a lot so between the normal torque and that they are usually pretty tight to get moving. One trick you can try, take a solid piece of steel like an extension or drift, set the tip of that item on the edge of the flat that retains the clutch. Like you were trying to shave the corner off the nut. Now give it a HARD hit with a hammer. OH be sure the belt is still on as you can't hold the pulley at the same time.
Like this - https://www.youtube.com/watch?v=AK-J1ZUATyg

Dec 12, 2025 at 5:53 PM
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PACKERS27
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I never thought of that. Ill give that a try. Do you think heating up the nut helps as well? Also, the holes on the pulley is not M8x125 like chatGPT says. Its smaller. Do you know what size those holes are,
Dec 12, 2025 at 5:59 PM
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STEVE W.
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It's been a while but I think they were M6, right around 1/4" in SAE.
Dec 12, 2025 at 8:03 PM
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PACKERS27
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That didnt fit. Its hard to thread any bolt behind it bc theres not alot of room. Where can I can the pulley wrench and what size is it? Also whats the size of the nut? I CANNOT get this off.
Dec 13, 2025 at 2:13 PM
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PACKERS27
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How confident that it loosens counter clockwise, there seems to be alot of confusion about it mindless the internet as some goes left. Some goes right. Here's a pic
Dec 13, 2025 at 3:10 PM
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STEVE W.
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That goes on clockwise so to remove it it has to come off counterclockwise.
Dec 13, 2025 at 3:43 PM
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PACKERS27
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Ok
Dec 14, 2025 at 10:35 AM
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STRAILER
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STEVE W. is one of our best! Please use 2CarPros anytime we are here to help.
Dec 15, 2025 at 11:45 AM
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PACKERS27
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Yes I can vouch for steve. I've been using the site for a very long time. You and Steve are the top guys in my opinion. The reason why I questioned the direction of how you loosen it is because I simply could not believe that it could be that hard to turn with the leverage that I was getting. I was using a propane torch and all kinds of things. But let me tell you what actually happened. I was at my Wit's End and I said screw it, I sprayed the crap out of it with WD-40 and came back to it today. I figured that it wasn't going to do me any good but I grabbed the pulley with one hand and I turned it with the other hand. Just like that. That easy. I guess it was in the power of the WD-40.
Dec 15, 2025 at 2:40 PM
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STEVE W.
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NAA, It just sensed that you were going to cut it off with a torch if it didn't move... I've had some that were VERY stuck, but I also have wrenches for them that most don't have. Those use an impact hammer to break them free.
Dec 15, 2025 at 3:04 PM
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PACKERS27
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Yeah I saw them today at a parts store but didn't have an air hammer. I was going to drill a small hole in the nut and use heat and PB Blaster to see if that would work but Im glad I got this off today
Dec 15, 2025 at 6:08 PM
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PACKERS27
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Just wanted to clarify that after everything I did, soaking it with WD40 and letting it sit for 12 hours, along with the proper pulley holder wrench made ALL the difference. Thank you guys so much
Dec 16, 2025 at 4:49 PM
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STRAILER
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wow, yep you went the extra mile on that one, nice work, use 2CarPros anytime we are here to help.
Dec 18, 2025 at 9:36 AM