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how to: replacing fan clutch

JonBishop

Well-Known Member
Messages
724
Location
Glendora, CA
i replaced my fan clutch and tried to do my own little "how to" so here it is

engine was running super hot while sitting, but while in motion stayed cool for most of the time.... so that immediatly told me i had a bad fan clutch, and the fact it wouldnt click on, and the fact alot of these very helpfull mrmbers on here helped me diagnos the issue :)


looking pretty hot "post replacement"

went and picked up a Hayden Fan Clutch from O'Reilly's Autoparts $59.99


then rented the fan clutch tools from O'Reilly's $74.99, full reinburstment when returned in 48hrs


so i let the Hummer sit for abit and cool down so i would have a nice and cool engine to work on...
then when i went to tackle it i removed the Radiator top hose for a easy removal of the fan shroud


next i slid the tabs on the shroud to twist the up so there would be enough cleance to get the shroud out and around the fan (you can locate the tab on the passanger side of the shroud and just push down on the locking mechinism then slide up till you cant slide no more and make sure the bottom of the shroud is twisted up so the shroud will come out nice and easy with enough cleance, relest the two tabs you need to pop up on eachside of the shroud as well)


one more thing is i took off my radiator cap to give alittle more cleance to get the shroud out
and then make sure you take it out carefully not to break or damage the radiator or anything else in the process, and bam, its out


once its out, the fun begins, youll be looking at this then

didnt get a chance to take action shots but to take it off you will need to do this... use the 36mm provided in the fan clutch tool kit that was rented or bought, and put it on the clutch nut, i found that if you use another clutch tool provided in the case, big enough to go around the 4 bolts behind the old fan clutch by the serpentine belt its easy to take off, so you put the 36mm on the fan clutch nut and the bigger fan clutch tool to go around the 4 bolts, its a super tight fit but itll work, you wanna push the 36mm tool towards the passanger side of the vehicle, just like taking a regular bolt off, and hold the other tool in place around the 4 bolts so itll unbolt, youll notice its tough so hit it with a hammer if you can to pop it loose, once its loose your golden...


youll be left with this, those are the 4 bolts i was talking about, one is hiding behind the place you just unscrewed.

to take out the old fan clutch you need a size 13mm wrench, and jus unscrew all four.


so now you have this, my fan was super dirty so i jus washed it up and dried it so it was nice and dirt free then i went ahead and installed the new fan clutch in, and pretty much jus reverse the steps from here...


new ones in, and happy with it, now the reinstall... make sure the 4 bolts are snug on there.


just spin it back on and be carefull not to cross thread, when it gets fully on, give it a couple tightening tugs to ensure the fan clutch nut is on securely.

then be sure to reinstall the fan shroud and twist the bottom back to its home spot and snap in the two corners and the two bottom pins, reinstall the top radiator hose, look and see that coolant levels are good, if not refill as necessary..

then turn the Hummer on and listen to that fan blow.


been 2 days since the install was done and wont go above 1/2 on the temp gauge, so all in all, very happy :)

hopefully this is helpful, if anyone has anyother suggestions on this process please dont hesitate to comment :)
 

cbetts

NERD!!!
Messages
3,182
Location
Rancho Palos Verdes, CA
Thanks for sharing this! I replaced my fan clutch last night in 45 minutes. I bought a Lisle 43600 Universal Fan Clutch Wrench Set from Amazon for $45 and Prime shipping. Almost needed a second set hands when reinstalling the shroud. That was a pain to get the pins to line-up on the bottom while jiggling it around.

It was good to hear the roar of the fan again. I am convinced it was the source of my cooling issues. I will find out Thursday when I drive to Lancaster for the weekend.
 

ALGSD

Probationary Member
Messages
1
Location
Tennessee
Hey Guys!
I thought I’d add an alternative method for replacing the fan clutch that does NOT involve removing the fan shroud, nor the upper radiator hose!
A no-mess solution! No need to rent a fan clutch tool either!

I do recommend wearing safety glasses for this method.

I’d add pictures but I don’t know how.

1. Rotate the lower portion of the radiator shroud fully open.
2. Remove the 4 bolts securing the plastic fan blade assembly to the fan clutch with a wrench. You’ll have to brace against it by wrapping your other hand around the fan blades. I left a couple bolts in but broken loose so the fan would not get in the way for the next step
3. Using a hammer and punch, align the punch to the left edge of the “hex” of the fan clutch nut. Pound with the hammer. May take multiple attempts to break the fan nut loose, after which it spins easily by hand. Only partially loosen the clutch. Remove the fan blade bolts if you haven’t already.
4. Get underneath the vehicle.
5. Using both hands, continue to loosen and remove the fan clutch, being careful not to allow the fan or the clutch to contact the radiator fins except gently
6. Sneak the clutch out whilst leaving the fan in the radiator shroud. I was able to separate them, place the fan clutch flat against the radiator core and resting against the lower tank of the radiator, and then i was able to raise the fan assembly above the clutch. Then i brought the fan clutch to the passenger side over near the transmission cooler lines, and there’s just enough space to lower the clutch from the vehicle

To install, follow steps in reverse. And for step 3, use the punch on the right edge of the clutch nut to cinch it. If you did that part right you won’t be able to spin the fan blades counterclockwise and loosen the nut.

Getting the fan clutch to thread back onto the water pump from underneath the vehicle is the hardest part.
Took maybe 30 minutes, but i was a mechanic in my younger years
 
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