Fan Clutch--Shean update II

scott shean

New member
Sep 26, 1998
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Jim, thanks for your interest.

When I saw you in late March, I was running the Hayden 2747, and complained
to you about the continuous noise below 45 MPH. You recommended the 2705,
which I installed when I returned to Baton Rouge. Since then, the 2705 has
not made a sound. I have been in situations, such as slowing down from
highway speeds on an exit ramp, where the original fan clutch would normally
engage, yet the 2705 remains silent. Additionally, at speeds of 70 MPH, the
temperature gage creeps up slightly above 1/4. (Something the original
clutch would not permit without engaging.) For these reasons, I don't think
that the Hayden 2705 is an exact duplicate of the OEM fan clutch.

Having said that, I would continue to recommend the 2705, at least for us
"flatlanders". I don't have experience with mountain driving, which might
change my opinion. However, the 2797, with its continuous engagement, is
totally unacceptable. The 2747 is better, but still unnecessarily loud in
city driving. If I were planning a trip through the mountains, or towing a
heavy trailer, I would purchase a 2747 and carry it as a spare in case the
2705 proved to be inadequate. My preference would be to have the OEM
clutch. But for now, I will stick with the Hayden 2705.

Best regards, and I hope we are not wearing out the readers.

Scott Shean
78 Royale
Baton Rouge, LA

>-----Original Message-----
>From: owner-gmcmotorhome
>[mailto:owner-gmcmotorhome]On Behalf Of Jim Bounds
>Sent: Tuesday, July 20, 1999 7:05 AM
>To: gmcmotorhome
>Subject: RE: GMC: Fan Clutch--Shean update
>
>
>Scott,
>I use the 2705 and have, as you found, had comparable results with the OEM.
> There is a balance between noise andair moving capacity and it seems the
>2705 does a good job at moving air while not driving you nuts.
>
>How is the 2705 performing? You said the temp. needle is at the same place
>as before, is that OK?
>
>I'm interested in what you think, I have recomended many customers to use
>the 2705 and all have been satisified.
>
>Jim Bounds
>Jim Bounds/Co-op Motor Works Orlando www.gmccoop.com
 
Mark, as best I can, I will try and answer your comments/questions as
follows:

>-----Original Message-----
>From: owner-gmcmotorhome
>[mailto:owner-gmcmotorhome]On Behalf Of Mark Grady

>Scott --
>I'm curious -- did you attempt to 'recalibrate' the 2747 so that it didn't
>engage at what you heard just a factor of the non-engaged fan
drive % of the one you got?

I have read on this GMCNet of the successful attempt of one person to change
the "engage" temperature of the fan clutch. In the last eight months, I
have installed all of the Hayden fan clutches, and it is not obvious to me
how you can "adjust" any of them.

>I'm like you... my original was fine till I put on a new water pump, it got
>laid down. Next thing you know, it was on all the time (bearing seized). I
>didn't know what the heck was wrong at first.

If you like "on all the time", get a Hayden 2797.

>Then I got the 2707 replacement, heard it engage, but only about 30~50% as
>loud as before. A/C performance suffered when driving in the city, and the
>A/C belt would squeal unless I kept it tighter than I liked.
>
>I've now put on a 2747. I haven't been on a long enough trip to
>know exactly
>what I've got... I'll know after this weekend, we're headed to Chicago.
>
>On my test drive, I didn't hear it fully engage, but it was louder at ~45
>than the 2707 I took off, and the A/C performance seems back to
>normal. (And
>it's been stinkin' hot here).

Mark, we live in south Louisiana, so I don't have to tell you about HOT. I
could not live with the Hayden 2747 because it would not disengage until 45
MPH. (And this was in April.) This is NOT how the OEM clutch operated. You
might want to look into an electric fan(s) on the front of the radiator to
improve the A/C performance.

Let's keep talking, and maybe we will get to the bottom of this "problem."

Scott Shean
78 Royale
Baton Rouge, LA
 
>I have read on this GMCNet of the successful attempt of one person to
change
>the "engage" temperature of the fan clutch. In the last eight months, I
>have installed all of the Hayden fan clutches, and it is not obvious to me
>how you can "adjust" any of them.

Use a dremmel tool with a cut-off wheel to cut additional slots in the
bracket that secures the fixed end of the thermostat. Move the fixed end of
the thermostat from slot to slot and keep in the one that works best. It
takes a bit of trial and error but you can usually find a good set point
(assuming that the clutch is good).

Dave
73 Sequoia
 
The Cinnabar OEM works best for me, the 2747 next best but sometimes too much
engagement, the 2797 works best but in terms of cooling but wastes gas because
it's on 98% of the time, especially when it's cold when you don't need it. If
you like the engagement that the 2797 has, you would be better served to simply
fabricate a fan shaft and run it direct drive and forget the clutch, but a waste
of gas and noisy. My opinion....

Phil Swanson

> Jim, thanks for your interest.
>
>
> . However, the 2797, with its continuous engagement, is
> totally unacceptable. The 2747 is better, but still unnecessarily loud in
> city driving. i
 
Is the Cinnabar OEM the AC/Delco # 15-4298 Paul Bartz wrote about or
something else?

Does anyone know?

|
|The Cinnabar OEM works best for me, the 2747 next best but
|sometimes too much
|engagement, the 2797 works best but in terms of cooling but wastes
|gas because
|it's on 98% of the time, especially when it's cold when you don't
|need it. If
|you like the engagement that the 2797 has, you would be better
|served to simply
|fabricate a fan shaft and run it direct drive and forget the
|clutch, but a waste
|of gas and noisy. My opinion....
|
|Phil Swanson
|
 
Has anyone tryed a flex fan? dick d

> The Cinnabar OEM works best for me, the 2747 next best but sometimes too much
> engagement, the 2797 works best but in terms of cooling but wastes gas because
> it's on 98% of the time, especially when it's cold when you don't need it. If
> you like the engagement that the 2797 has, you would be better served to simply
> fabricate a fan shaft and run it direct drive and forget the clutch, but a waste
> of gas and noisy. My opinion....
>
> Phil Swanson
>

>
> > Jim, thanks for your interest.
> >
> >
> > . However, the 2797, with its continuous engagement, is
> > totally unacceptable. The 2747 is better, but still unnecessarily loud in
> > city driving. i
 
Yup,
it got removed relatively quickly, noise being the biggest objection.
It was quite a while ago but I don't think it stayed on long enough to get a
workout, just long enough to get a GM fan clutch. Just too much noise for
me.
Note I say GM fan clutch... tried several non-GM but they just didn't last.

And don't forget.... don't lay it down when removed once installed. Keep it
upright, i.e. in operating position.

Heinz

>Has anyone tryed a flex fan? dick d
>

>
>> The Cinnabar OEM works best for me, the 2747 next best but sometimes too
much
>> engagement, the 2797 works best but in terms of cooling but wastes gas
because
>> it's on 98% of the time, especially when it's cold when you don't need
it. If
>> you like the engagement that the 2797 has, you would be better served to
simply
>> fabricate a fan shaft and run it direct drive and forget the clutch, but
a waste
>> of gas and noisy. My opinion....
>>
>> Phil Swanson
>>

>>
>> > Jim, thanks for your interest.
>> >
>> >
>> > . However, the 2797, with its continuous engagement, is
>> > totally unacceptable. The 2747 is better, but still unnecessarily loud
in
>> > city driving. i
>
>
 
>
> Also, if these things shouldn't be layed down, how are they kept vertical
> 'til you buy them?

It's once they've been installed you should not lay them down anymore. I.e.
if you take your rad out stand the cluch up against the wall after removing
it or better yet, hang it on a nail on the wall so it doesn't get tipped
over.

Heinz

>
> TIA
>
> ___________
> Dave (& Dege), '76 Royale /_][__] [_] | "SR JAMES"
> Santa Barbara, CA *0-------OO--* (our hobby)
>
>
>
 
I've seen the part number for the AC/Delco fan clutch posted as 14-4208 and
14-4298.
Which is correct?

Also, if these things shouldn't be layed down, how are they kept vertical
'til you buy them?

TIA

___________
Dave (& Dege), '76 Royale /_][__] [_] | "SR JAMES"
Santa Barbara, CA *0-------OO--* (our hobby)