GM Radiator Fan - What I discovered of interest to all

GordnadoCRD · **Posted:** Mon Aug 06, 2018 12:30 pm

https://www.ebay.com/itm/Cooling-Fan-Cl ... m570.l1313

https://www.ebay.com/itm/Heavy-Duty-Coo ... m570.l1313

WWDiesel · **Posted:** Mon Aug 06, 2018 12:31 pm

Found the Hayden specs listed in their online PDF catalog:

2786 D REV 6.45 M30x1.5 RIGHT .70 1.44 [36mm] HEX 1.75 3.25 2.52 4.59 M10x1.5 HOLE (4)
2986 D REV 6.45 M30x1.5 RIGHT .70 1.44 [36mm] HEX 1.75 3.25 2.52 3.77 M10x1.5 HOLE (4)

Specs are identical and both are listed as "Severe Duty" clutches!
Not sure what the differences are?
Amazon does still list the 2986 for purchase:> https://www.amazon.com/s?url=search-alias%3Daps&field-keywords=hayden+2986
NAPA crosses the 2986 to TEM 271625:> https://www.napaonline.com/en/p/TEM271625

:SOMBRERO:

GordnadoCRD · **Posted:** Mon Aug 06, 2018 12:47 pm

Although I have had no problems with mine, others have found recent Hayden quality to be lacking, so finding an alternate source may be a good thing. They do exist.

Jett · **Joined:** Fri Apr 17, 2020 12:07 am **Posts:** 250

Nailed this mod down tonight! Wasn’t too bad, had to make a tool to hold the pulley and rented a kit to break the nut but after that it was pretty easy. I couldn’t find a Napa part but orieleys had a Murray 2786 in stock, $60 that appeared to be the part in a different flavor. Holding the stock fan next to the new one made it clear how this mod is an improvement.

Also noticed that there is a big gap at the base of the shroud that seems like it could be losing a lot of air. I might try to fix that. There’s a thin plastic piece added in that seems like it should be doing that but it is not sufficiently filling it.

WWDiesel · **Posted:** Thu Aug 20, 2020 11:41 pm

GordnadoCRD wrote:

Although I have had no problems with mine, others have found recent Hayden quality to be lacking, so finding an alternate source may be a good thing. They do exist.

FYI:
A couple of alternate part numbers I have on file for the fan clutch:
ACDelco PN 20913877
Four Seasons 36973
Severe Duty; w/ Heavy Duty Tow Pkg.; w/ AC

Jett · **Joined:** Fri Apr 17, 2020 12:07 am **Posts:** 250

Could add Murray 2786 to the list of clutches, confirmed to work and cheaper too. Doesn’t give a country of origin or parent company so?

jeepsterkj · **Joined:** Mon Jun 11, 2018 7:38 am **Posts:** 52

Back on October 21st, I took off my OEM 5 bladed metal fan from my 2.8 CRD and fitted the 11 blade plastic fan from the 3.7 gasser instead, after reading this was recommend mod.
The clutch that came with the plastic fan is smaller but it has the exact same fixing holes, and four fixing bolts, as the OEM CRD clutch has, meaning the clutches are interchangeable.
So I simply swapped the CRD clutch over to the plastic fan, figuring a CRD clutch is obviously made specifically to suit a CRD engine and a 3.7 clutch is obviously made specifically to suit a 3.7 gasser...So it made sense to keep the same clutch when I changed the fan. Obviously it will still work with the 3.7 clutch, but it may not kick in when it's supposed to because the 3.7 gets hotter than the CRD.
It only takes a couple of mins to change the clutches over anyway (it's only four bolts) so it's not like huge problem to do so.

Another thing to consider is the plastic fan/CRD clutch combo is 500g lighter than the OEM metal fan with the same clutch and the 3.7 clutch is even lighter, so there should also be slightly less wear and tear on the Serp' belt with this combo due to having less inertia to overcome.

In fact I would have liked an even lighter plastic fan instead...Specifically, the very little known 7 bladed plastic fan off the KK, but a used KK fan cost almost 3 times more than the used 11 blade KJ fan did!
The 7 Blade KK fan is never talked about on KJ forums so it seems no one but me knows it exists (till now), and I only discovered it by accident when looking for the 11 blade...In my present financial situation the 11 blade was all I could afford but I would love to know how well the KK fan suits the CRD as it might be a whole Kilo lighter that the 11 blade, and with less blades, which look to be about the same pitch from the pictures of it, it should absorb less engine power to turn it, and therefore give better fuel economy than the 11 blade...It certainly might be one of the factors that reduces the KK's fuel consumption in comparison to the KJ?

I paid £25 for the used 3.7 fan, plus postage, on ebay, and it came the next day!

Even after cleaning any grease off it as best I could, it still looked like a used fan...Seems the plastic used must be Nylon, which can absorb water, and therefore dissolved dirt in any water hitting the fan can actually be drawn into it along with the water, permanently darkening the plastic.

Anyway, cosmetics aside, it definitely seems to blow more air at tick over than the OEM metal fan did, as I could feel the extra airflow blowing on my hair when standing over the bonnet, but despite this, I would say it is definitely quieter than the metal fan too, so I would say it is a worthy upgrade.

WWDiesel · **Posted:** Tue Dec 01, 2020 2:49 pm

jeepsterkj wrote:

So I simply swapped the CRD clutch over to the plastic fan, figuring a CRD clutch is obviously made specifically to suit a CRD engine and a 3.7 clutch is obviously made specifically to suit a 3.7 gasser...So it made sense to keep the same clutch when I changed the fan. Obviously it will still work with the 3.7 clutch, but it may not kick in when it's supposed to because the 3.7 gets hotter than the CRD.

The 3.7 gasser plastic fan will certainly bolt up and work. If you can find a used 11 blade 3.7 gasser fan it will be the cheapest route to take since it will bolt right up to CRD factory fan clutch, but it cannot provide the same amount of cooling as the GM 11 blade fan & fan clutch modification.

There are two major things to consider as to why going to the GM fan & fan clutch may be a much better combination.
1. If you are buying new parts, the GM fan & fan clutch are much cheaper than the Mopar 3.7 gasser parts, about 1/2 the cost, and can be bought at your NAPA store.
2. The GM fan & fan clutch that were designed and used on Heavy Duty 6.6. V8 engines came from the factory with heavy duty cooling systems with AC and tow packages. So the larger fan clutch will provide a better cooling profile than the Mopar 3.7 gasser clutch. The GM fan also sets slightly closer to the radiator stack.

Driving in the very hot 100+ temperatures along with very high humid summer conditions we sometimes have in the south, I can attest to the vast improvement to the AC performance the GM fan & fan clutch makes to the Jeep CRD especially in low speed and stop and go in town driving. With the GM fan and fan clutch, I never see the engine or transmission temperatures rise much above normal anymore especially when towing a loaded trailer and the AC actually still cools setting in stop and go driving. The 11 blade GM fan moves a huge amount of more air flow as compared to a stock metal fan.
:BANANA:

jeepsterkj · **Joined:** Mon Jun 11, 2018 7:38 am **Posts:** 52

WWDiesel wrote:

jeepsterkj wrote:

So I simply swapped the CRD clutch over to the plastic fan, figuring a CRD clutch is obviously made specifically to suit a CRD engine and a 3.7 clutch is obviously made specifically to suit a 3.7 gasser...So it made sense to keep the same clutch when I changed the fan. Obviously it will still work with the 3.7 clutch, but it may not kick in when it's supposed to because the 3.7 gets hotter than the CRD.

The 3.7 gasser plastic fan will certainly bolt up and work. If you can find a used 11 blade 3.7 gasser fan it will be the cheapest route to take since it will bolt right up to CRD factory fan clutch, but it cannot provide the same amount of cooling as the GM 11 blade fan & fan clutch modification.

There are two major things to consider as to why going to the GM fan & fan clutch may be a much better combination.
1. If you are buying new parts, the GM fan & fan clutch are much cheaper than the Mopar 3.7 gasser parts, about 1/2 the cost, and can be bought at your NAPA store.
2. The GM fan & fan clutch that were designed and used on Heavy Duty 6.6. V8 engines came from the factory with heavy duty cooling systems with AC and tow packages. So the larger fan clutch will provide a better cooling profile than the Mopar 3.7 gasser clutch. The GM fan also sets slightly closer to the radiator stack.

Driving in the very hot 100+ temperatures along with very high humid summer conditions we sometimes have in the south, I can attest to the vast improvement to the AC performance the GM fan & fan clutch makes to the Jeep CRD especially in low speed and stop and go in town driving. With the GM fan and fan clutch, I never see the engine or transmission temperatures rise much above normal anymore especially when towing a loaded trailer and the AC actually still cools setting in stop and go driving. The 11 blade GM fan moves a huge amount of more air flow as compared to a stock metal fan.
:BANANA:

Are you 100% sure the 3.7 V6 11 blade plastic fan is not identical to the GM 11 blade plastic fan? If so, what are differences?

WWDiesel · **Posted:** Sat Dec 05, 2020 9:28 pm

jeepsterkj wrote:

Are you 100% sure the 3.7 V6 11 blade plastic fan is not identical to the GM 11 blade plastic fan? If so, what are differences?

Yes, I am 100% sure they are not the same!
They are NOT identical, I think the only similarities they both have in common is they both have 11 blades and are plastic, it ends there!
As to angles and overall diameter, I never did measure the GM fan and I did not have a 11 blade Mopar fan to compare measurements and prosperities against.
One big difference is cost; price and compare the cost of the GM fan & fan clutch versus the Mopar 11 blade fan and fan clutch, the GM parts cost wise are almost half what the Mopar parts cost.

The GM 11 blade plastic fan will not bolt up to the smaller Mopar fan clutch, the bolt patterns are different.
The GM fan uses slightly larger bolts in a slightly larger bolt pattern to bolt the GM fan to the larger Heavy Duty 6.6 GM V8 fan clutch.

jagster936 · **Joined:** Sun Aug 04, 2019 3:06 pm **Posts:** 210

thatoneguy wrote:

Thanks, not sure what the heck is going on but now it is unlocking after a short drive after firing up for the last 3 days. And after a long hill pull will kick on for a bit and seem to unlock again when back level cruising. I can really feel/hear when its locked and unlocked and now seems to be functioning pretty much spot on. I will keep this in mind if it does act up again.

That's interesting. I can never notice mine lock or unlock ever, even in sweltering Texas heat or cold winters. I suspect its locked in or at some set locking position. At idol it makes a soft fan sound like it's moving good air. Not sure lol

jagster936 · **Joined:** Sun Aug 04, 2019 3:06 pm **Posts:** 210

I can only compare to my Tacoma - when I start it makes a loud roar and then calms down to no sound at all and rarely makes much sound. Maybe slight small fan noise when really hot with AC on..and after stopping it a while. I would say that is functioning properly.

The jeep never makes a loud roar starting it or any other time. Does anyones?

PZKW108 · **Joined:** Sun Apr 06, 2014 5:23 pm **Posts:** 461

figuring a CRD clutch is obviously made specifically to suit a CRD engine and a 3.7 clutch is obviously made specifically to suit a 3.7 gasser...

Following that logic you might as well keep the stock fan as well !

TURBO-DIESEL-FREAK · **Joined:** Sat Apr 17, 2010 3:29 pm **Posts:** 1167

FOLLOWING...

WWDiesel · **Posted:** Fri Apr 15, 2022 6:04 pm

When I first start off with mine, I hear the roar of the fan for a short distance, but I do have the V8 GM 11 blade fan and fan clutch cooling upgrade.
Never heard any noise with the old metal fan blade and stock fan clutch which did not provide adequate cooling when towing a 4k load on hot summer days.

After installing the 11 blade V8 GM fan and fan clutch, temperature never moves beyond the 11:30 position on the temperature gauge.
And and very big plus; the AC works so much better especially in stop and go traffic in town on super hot 100+ temperature days when the humidity is in the 90's.... :BANANA:

Worth every penny of the conversion upgrade for better cooling!

taroo · **Joined:** Sun Apr 27, 2008 2:14 pm **Posts:** 271

Sounds like another upgrade for me. So wonder why the clutch number you used has two different items:

WWDiesel wrote:

When I first start off with mine, I hear the roar of the fan for a short distance, but I do have the V8 GM 11 blade fan and fan clutch cooling upgrade.
Never heard any noise with the old metal fan blade and stock fan clutch which did not provide adequate cooling when towing a 4k load on hot summer days.

After installing the 11 blade V8 GM fan and fan clutch, temperature never moves beyond the 11:30 position on the temperature gauge.
And and very big plus; the AC works so much better especially in stop and go traffic in town on super hot 100+ temperature days when the humidity is in the 90's.... :BANANA:

Worth every penny of the conversion upgrade for better cooling!

WWDiesel · **Posted:** Tue Apr 26, 2022 1:30 pm

There are differences between the two part numbers.
TEM 271312 is standard duty and the TEM 271625 is severe duty with AC and towing package.

If you are buying from NAPA, you want the TEM 271625
Important Information: CCW; w/ Severe Duty Fan Clutch; w/ Heavy Duty Towing Package; w/ Air Conditioning

More Fan Clutch part numbers:
ACDelco PN: 20913877 / Hayden Fan Clutch PN: HY 2786 / Four Seasons PN: 36973

Reminder; GM 11 blade fan requires four(4) GM 11516869 bolts M10X1.5X18

jagster936 · **Joined:** Sun Aug 04, 2019 3:06 pm **Posts:** 210

I had same issue as taroo. They list two fans and the severe duty rated one from NAPA is out of stock

How do I know which other ones are "severe duty" from those alternate brands? Are they all the same? What is the difference in the standard one as napa does stock it?

Oreily has the "hayden" 2786 or they call it part line "MTC" or "Murray". I guess this is all the same, but is it the same severe duty or whatever rating? Part numbers are so annoying. I saw the real AC Delco version on amazon

https://www.amazon.com/Genuine-GM-20913 ... B007RP4RUK

It costs quite a bit more but if it's better quality or severe duty vs not..I'm willing to pay.

Thx

WWDiesel · **Posted:** Tue Jun 07, 2022 3:17 pm

These are the part numbers:
NAPA Part no’s (fitment: Chevrolet Truck)
GM Severe Duty Fan Clutch NAPA PN: 271625
GM 11 blade HD Cooling Fan NAPA PN: 8552223
Requires four (4) GM 11516869 mounting bolts M10X1.5X18mm (mounts fan to clutch)

The GM fan & fan clutch is designed for the GM 6.0L V8 engine with HD cooling, AC, w/towing package.
ACDelco Fan Clutch PN 20913877

Hayden Fan Clutch PN: HY 2786 or 2986 or Four Seasons PN: 36973
ACDelco GM11 blade fan: PN: 15976889

Amazon has the Hayden 2786 listed online at:> https://www.amazon.com/Hayden-Automotiv ... B000C3DD5E

jagster936 · **Joined:** Sun Aug 04, 2019 3:06 pm **Posts:** 210

Yea, napa doesn't have the severe duty one. I was actually able to source everything at Oreilly's and my local store had it all, even m10-1.5x20mm bolts, with two washers, should work. If not I may use 16mm (from NAPA). I grabbed both. I will leave part numbers for the fan; clutch is what you list there but "Murray." She crossed checked the fan and found another part number for fan. And they had it!

GM Radiator Fan - What I discovered of interest to all

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