Recommended Clutch Fan?

[Stocker]

My OEM fan clutch is showing signs of wear and I plan to replace it before long. It's weeping a bit of fluid near the shaft and the fan has a tiny bit of wobble. Online shopping has turned up several that will fit, but I'm not sure if some are better than others. Any that you like, or any that you would avoid? Right now I'm leaning towards an ACDelco 15-80245 which *may* be an identical replacement. Thanks.

[davepl]

I bought this one - not the cheapest but I too wanted ACDelco. Amazon lists it as a direct fit, but it's not cosmetically identical to the old ones. Close though.

https://www.amazon.com/gp/product/B0...?ie=UTF8&psc=1

[Stocker]

Yup, they show that as correct for your big-block GMC, and 15-80245 for my SBC.

So you are happy with the way yours works? Engages and disengages when it should? Curious because I have read about some units being too aggressive (for lack of a better word), locking up too early and staying locked for too long, creating power loss and extra noise.

[davepl]

Originally Posted by Stocker

Yup, they show that as correct for your big-block GMC, and 15-80245 for my SBC.

So you are happy with the way yours works? Engages and disengages when it should? Curious because I have read about some units being too aggressive (for lack of a better word), locking up too early and staying locked for too long, creating power loss and extra noise.

No complaints from me. Works as expected. Seems just a bit tighter than my (probably still working) original, as you'd probably think it should.

Seems to tighten up an appropriate amount for the heat load.

[Tom Vogel]

I have a Real AC Delco brand new in the box that you can have for $75 plus shipping. I paid way over $100 bucks when I bought it.

[Stocker]

The one I have been looking at claims to be AC Delco. If you don't mind my asking, is there a difference between yours and that one? What's the p/n on yours? Thanks.

[Tom Vogel]

Hows this? if you cant read it, the number is 22050676 This a Real GM clutch fan, not a chinese knockoff... Dayton Ohio, USA made.

[jr1000yarder]

I just got mine from GM. Part #19189681

1969 396

Says made in USA on the clutch....

[Stocker]

Thanks for the feedback, guys, I appreciate it. And thanks for the offer, Tom. That unit may do the trick but it does look different than mine, and the p/n is different. I'm going to do more digging before I commit.

[Tom Vogel]

Mine is for a smallblock.

[Stocker]

Update, and I'll keep it brief. There are three types of thermal fan clutches -- standard duty, heavy duty, and severe duty. Good explanations / illustrations here: http://www.haydenauto.com/featured%2...s/content.aspx

My K20 uses a heavy duty unit but I could not find one. Virtually all are standard duty, and a very few are severe duty. Went to my local NAPA and another customer overheard us and suggested looking up the part for a slightly newer K30. Bingo! NAPA p/n 271303, fan clutch #2747. Made by Four Seasons in Lewisville, Texas.

Tom, I have to pass on yours. It is a standard duty and not recommended for my K20.

[samkost]

Tom,
Is the Delco clutch fan you have, a thermal or non-thermal?
I made a similar post about replacing mine and wonder if the part you have is a direct replacement. Forum members answered suggesting that I get a thermal style for replacement.
Thanks
Sam

[FoxCustom]

Originally Posted by Stocker

Update, and I'll keep it brief. There are three types of thermal fan clutches -- standard duty, heavy duty, and severe duty. Good explanations / illustrations here: http://www.haydenauto.com/featured%2...s/content.aspx

My K20 uses a heavy duty unit but I could not find one. Virtually all are standard duty, and a very few are severe duty. Went to my local NAPA and another customer overheard us and suggested looking up the part for a slightly newer K30. Bingo! NAPA p/n 271303, fan clutch #2747. Made by Four Seasons in Lewisville, Texas.

Tom, I have to pass on yours. It is a standard duty and not recommended for my K20.

Stocker, Great info on the heavy duty clutch. I currently am running a fixed blade setup in my '87 V20 and I'd like to level out the temp especially since it's getting cold here.

I'm having trouble finding the actual fan blades themselves to run with this clutch! Any recommendations?

[Stocker]

Originally Posted by FoxCustom

Stocker, Great info on the heavy duty clutch. I currently am running a fixed blade setup in my '87 V20 and I'd like to level out the temp especially since it's getting cold here.

I'm having trouble finding the actual fan blades themselves to run with this clutch! Any recommendations?

The OEM 7-blade fan on my K20 with factory A/C might be the best possible choice. Mine is 18" diameter but your '87 might be different (and some big-blocks use a 19.5" fan) so the first step is to measure yours. Original fans sometimes come up for sale on the parts board here. Aftermarket suppliers like Summit, Brothers, and Classic Industries are worth a look too.

[FoxCustom]

Originally Posted by Stocker

The OEM 7-blade fan on my K20 with factory A/C might be the best possible choice. Mine is 18" diameter but your '87 might be different (and some big-blocks use a 19.5" fan) so the first step is to measure yours. Original fans sometimes come up for sale on the parts board here. Aftermarket suppliers like Summit, Brothers, and Classic Industries are worth a look too.

Cool, I'll keep my eyes peeled for an original fan and then just have that NAPA heavy duty clutch ready to go once I find it. I believe my current fan is around 19 3/8"-19 1/5" OD.

Thank you for the info!

[1968_K20_4x4]

Originally Posted by Stocker

Update, and I'll keep it brief. There are three types of thermal fan clutches -- standard duty, heavy duty, and severe duty. Good explanations / illustrations here: http://www.haydenauto.com/featured%2...s/content.aspx

My K20 uses a heavy duty unit but I could not find one. Virtually all are standard duty, and a very few are severe duty. Went to my local NAPA and another customer overheard us and suggested looking up the part for a slightly newer K30. Bingo! NAPA p/n 271303, fan clutch #2747. Made by Four Seasons in Lewisville, Texas.

Tom, I have to pass on yours. It is a standard duty and not recommended for my K20.

Hello Stocker,

I have a question for you regarding your fan clutch. How did you determine that your K20 required a heavy duty unit, as opposed to the standard duty one?

I am looking to install a clutch fan set up in my '72 K20 as well, and all my research so far has pointed me to the Hayden 2705 fan clutch (Standard duty) as being correct for my truck. Did you go with the heavy duty unit because your truck is an A/C truck?
Mine has no A/C and manual transmission.

I am looking to use the 18 inch Derale 17118 fan as mentioned above, but I am not sure if I should go with the 2705 fan clutch or the Heavy duty 2747 as you are running. I am setting up my truck to haul a 22ft camper trailer on occasion.

Thanks for any input!

[Stocker]

Originally Posted by 1968_K20_4x4

Hello Stocker,

I have a question for you regarding your fan clutch. How did you determine that your K20 required a heavy duty unit, as opposed to the standard duty one?

I am looking to install a clutch fan set up in my '72 K20 as well, and all my research so far has pointed me to the Hayden 2705 fan clutch (Standard duty) as being correct for my truck. Did you go with the heavy duty unit because your truck is an A/C truck?
Mine has no A/C and manual transmission.

I am looking to use the 18 inch Derale 17118 fan as mentioned above, but I am not sure if I should go with the 2705 fan clutch or the Heavy duty 2747 as you are running. I am setting up my truck to haul a 22ft camper trailer on occasion.

Thanks for any input!

You're on the right track! My K20 does have factory A/C. Also, the original fan clutch was a heavy duty unit. Interestingly, my local NAPA store listed only a standard duty unit for my truck, but their information was incorrect. Either fan clutch should work well for you, although towing your camp trailer *might* require additional cooling. I would also suggest considering a 7-blade fan. Mine is factory, and is quiet.

If you haven't already seen it, Hayden's website shows the differences between clutch types. https://www.haydenauto.com/en/produc...-types/thermal

[1968_K20_4x4]

Originally Posted by Stocker

You're on the right track! My K20 does have factory A/C. Also, the original fan clutch was a heavy duty unit. Interestingly, my local NAPA store listed only a standard duty unit for my truck, but their information was incorrect. Either fan clutch should work well for you, although towing your camp trailer *might* require additional cooling. I would also suggest considering a 7-blade fan. Mine is factory, and is quiet.

If you haven't already seen it, Hayden's website shows the differences between clutch types. https://www.haydenauto.com/en/produc...-types/thermal

Thanks for the reply and for that link- very good info there!

I think a 7 blade fan would be perfect for my truck, but when I did some looking I couldn't find one that specifically fit our trucks. Do you happen to have a part number for your factory original one that I could use to help me search?

[Stocker]

Guys, if I may, Tom's Delco above is a standard duty thermal. The above link clearly shows how to make the determination.

[samkost]

Thanks for clarifying Mike.....I went to that site to read the differences but it obviously didn't sink into my thick skull
I'm learning.....

[Stocker]

Just to follow-up. I installed the new fan clutch yesterday. With the old one off, I could see it had seeped out a lot more fluid than I had thought. The shaft and the rear of the unit were heavily coated with built-up gunk. On a side note, I had also been unsuccessfully chasing what sounded like an occasional fan belt squeal. It would only happen around 1200-1300 rpm.

Took her out for a test run this morning. Temp gauge stayed at the lower end of normal, which is right where it usually reads. Went up the mountain and it climbed to a bit below halfway, typical for the situation. And I cannot create the 'squealing fan belt' noise. I suspect it was coming from the old fan clutch since it had lost a significant amount of fluid. Everything seems to be working just like it's supposed to.

[LostMy65]

Saved for reference.

[davepl]

I ordered this Delco one for my 402, but when it arrived it had the Severe Duty style and shape, not like pictured.

https://www.amazon.com/gp/product/B0...?ie=UTF8&psc=1

[Stocker]

Severe Duty *might* be overkill (stay engaged too much, extra roar, use a bit more fuel) or it might be just what that big engine wants. Are you planning to keep it, or return it and get a Heavy Duty unit?

[davepl]

It doesn't seem to run too much or make any additional noise, so I kept it and am running it!