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| [GMCnet] New Fan Clutch and noisy belts... [message #96407] |
Thu, 19 August 2010 10:39  |
kelvin
Messages: 608
Registered: February 2004
Location: Eugene, OR
Karma: 0
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Installed an Autozone 92-2797 fan clutch last night. Seems to work ok
with the testing I could do. Only 83° but I have a nice, steep test
hill. It got fully engaged a few times.
The problem is that when it does engage the belts start squealing like
crazy. Backing off the gas a bit makes the squeal stop but that doesn't
work well when climbing a big hill.
Noticed this the few times the old clutch would engage on my last trip, too.
I'm thinking I need a dual alternator pulley and belts but if it's the
fan clutch making the belts squeal then it's not an Alternator problem.
It's the water pump pulley that is squealing, no? And that already HAS
two belts on it.
Time for new belts? They might have 10,000 miles on them. Maybe 6
years old. Didn't keep good records of when I replaced them last.
Still look to be in great shape.
What say ye?!
Kelvin
'73 23'
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| Re: [GMCnet] New Fan Clutch and noisy belts... [message #96410 is a reply to message #96407] |
Thu, 19 August 2010 11:01  |
James Hupy
Messages: 6806
Registered: May 2010
Karma: -62
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Kelvin, look at the belt relationship to the sides of the pullies. Are they
riding well below the outboard edge of the pulley? They can be quite worn
and still appear new with no cracks. Take the belt between your thumb and
finger and rotate it. If you can rotate it much past 90 -110 degrees, it is
probably not tight enough. Belts are driven off the sides of the flanges and
depend upon tension to keep them from slipping. 35 year old pullies also
become worn, so you may have a combination of wear between them and the
belts. Too tight and the water pump bearings and alternator bearings will
suffer shortened life. I figure if one belt is worn that all of them have
the same number of hours on them, and I replace them all. Remember that some
of those belts stocked by your favorite auto parts store may have been
hanging there exposed to ceiling heat and ozone for several years. Kinda
like tires, old before we buy them. Isn't running old stuff fun?
Jim Hupy
Salem, Or
78 Royale 403
On Thu, Aug 19, 2010 at 8:39 AM, Kelvin Dietz <kelvin@datsuns.com> wrote:
> Installed an Autozone 92-2797 fan clutch last night. Seems to work ok
> with the testing I could do. Only 83° but I have a nice, steep test
> hill. It got fully engaged a few times.
>
> The problem is that when it does engage the belts start squealing like
> crazy. Backing off the gas a bit makes the squeal stop but that doesn't
> work well when climbing a big hill.
>
> Noticed this the few times the old clutch would engage on my last trip,
> too.
>
> I'm thinking I need a dual alternator pulley and belts but if it's the
> fan clutch making the belts squeal then it's not an Alternator problem.
> It's the water pump pulley that is squealing, no? And that already HAS
> two belts on it.
>
> Time for new belts? They might have 10,000 miles on them. Maybe 6
> years old. Didn't keep good records of when I replaced them last.
> Still look to be in great shape.
>
> What say ye?!
>
> Kelvin
> '73 23'
> _______________________________________________
> GMCnet mailing list
> List Information and Subscription Options:
> http://temp.gmcnet.org/cgi-bin/mailman/listinfo/gmclist
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| Re: [GMCnet] New Fan Clutch and noisy belts... [message #96427 is a reply to message #96410] |
Thu, 19 August 2010 11:55 |
Ray Erspamer
Messages: 1707
Registered: May 2007
Location: Milwaukee Wisconsin
Karma: -3
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Senior Member |
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Kelvin, I would recommend you put on the dual alternator pulley, best thing I
ever did. No more squealing belts !
Ray
Ray & Lisa Erspamer
78 Royale Center Kitchen
TZE368V101144
Wauwatosa, Wisconsin 53226
Email: 78GMC-Royale@att.net
414-745-3188
Web Site: http://ray-lisa.page.tl/
________________________________
From: James Hupy <jamesh1296@gmail.com>
To: gmclist@temp.gmcnet.org
Sent: Thu, August 19, 2010 11:01:30 AM
Subject: Re: [GMCnet] New Fan Clutch and noisy belts...
Kelvin, look at the belt relationship to the sides of the pullies. Are they
riding well below the outboard edge of the pulley? They can be quite worn
and still appear new with no cracks. Take the belt between your thumb and
finger and rotate it. If you can rotate it much past 90 -110 degrees, it is
probably not tight enough. Belts are driven off the sides of the flanges and
depend upon tension to keep them from slipping. 35 year old pullies also
become worn, so you may have a combination of wear between them and the
belts. Too tight and the water pump bearings and alternator bearings will
suffer shortened life. I figure if one belt is worn that all of them have
the same number of hours on them, and I replace them all. Remember that some
of those belts stocked by your favorite auto parts store may have been
hanging there exposed to ceiling heat and ozone for several years. Kinda
like tires, old before we buy them. Isn't running old stuff fun?
Jim Hupy
Salem, Or
78 Royale 403
On Thu, Aug 19, 2010 at 8:39 AM, Kelvin Dietz <kelvin@datsuns.com> wrote:
> Installed an Autozone 92-2797 fan clutch last night. Seems to work ok
> with the testing I could do. Only 83° but I have a nice, steep test
> hill. It got fully engaged a few times.
>
> The problem is that when it does engage the belts start squealing like
> crazy. Backing off the gas a bit makes the squeal stop but that doesn't
> work well when climbing a big hill.
>
> Noticed this the few times the old clutch would engage on my last trip,
> too.
>
> I'm thinking I need a dual alternator pulley and belts but if it's the
> fan clutch making the belts squeal then it's not an Alternator problem.
> It's the water pump pulley that is squealing, no? And that already HAS
> two belts on it.
>
> Time for new belts? They might have 10,000 miles on them. Maybe 6
> years old. Didn't keep good records of when I replaced them last.
> Still look to be in great shape.
>
> What say ye?!
>
> Kelvin
> '73 23'
> _______________________________________________
> GMCnet mailing list
> List Information and Subscription Options:
> http://temp.gmcnet.org/cgi-bin/mailman/listinfo/gmclist
>
_______________________________________________
GMCnet mailing list
List Information and Subscription Options:
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Ray Erspamer
78 GMC Royale Center Kitchen
403, 3.70 Final Drive
Holley Sniper Quadrajet EFI System,
Holley Hyperspark Ignition System
414-484-9431
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| Re: [GMCnet] New Fan Clutch and noisy belts... [message #96430 is a reply to message #96427] |
Thu, 19 August 2010 12:11 |
KRDietz
Messages: 133
Registered: July 2010
Karma: 0
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Senior Member |
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But the batteries were totally charged (just unplugged the coach before
driving it) so the Alternator wasn't even working to speak of. The belt
wasn't slipping on the alternator pulley Theoretically the water pump
pulley was slipping with the fan clutch engaged. And that WP pulley
already has two belts driving it.
Don't think there would be any help with dual alternator belts.
Oh... and when you do that doesn't the "grip" on the power steering pump
get lower, too? The one belt that drives the water pump and PS pump has
a lot of engagement on that PS pump pulley. You lose that when you go
to dual Alternator belts, right?
Kelvin
> Kelvin, I would recommend you put on the dual alternator pulley, best thing I
> ever did. No more squealing belts !
>
> Ray
>
>
> Ray & Lisa Erspamer
> 78 Royale Center Kitchen
> TZE368V101144
> Wauwatosa, Wisconsin 53226
> Email: 78GMC-Royale@att.net
> 414-745-3188
> Web Site: http://ray-lisa.page.tl/
>
>
>
>
> ________________________________
> From: James Hupy <jamesh1296@gmail.com>
> To: gmclist@temp.gmcnet.org
> Sent: Thu, August 19, 2010 11:01:30 AM
> Subject: Re: [GMCnet] New Fan Clutch and noisy belts...
>
> Kelvin, look at the belt relationship to the sides of the pullies. Are they
> riding well below the outboard edge of the pulley? They can be quite worn
> and still appear new with no cracks. Take the belt between your thumb and
> finger and rotate it. If you can rotate it much past 90 -110 degrees, it is
> probably not tight enough. Belts are driven off the sides of the flanges and
> depend upon tension to keep them from slipping. 35 year old pullies also
> become worn, so you may have a combination of wear between them and the
> belts. Too tight and the water pump bearings and alternator bearings will
> suffer shortened life. I figure if one belt is worn that all of them have
> the same number of hours on them, and I replace them all. Remember that some
> of those belts stocked by your favorite auto parts store may have been
> hanging there exposed to ceiling heat and ozone for several years. Kinda
> like tires, old before we buy them. Isn't running old stuff fun?
> Jim Hupy
> Salem, Or
> 78 Royale 403
>
> On Thu, Aug 19, 2010 at 8:39 AM, Kelvin Dietz <kelvin@datsuns.com> wrote:
>
>
>> Installed an Autozone 92-2797 fan clutch last night. Seems to work ok
>> with the testing I could do. Only 83° but I have a nice, steep test
>> hill. It got fully engaged a few times.
>>
>> The problem is that when it does engage the belts start squealing like
>> crazy. Backing off the gas a bit makes the squeal stop but that doesn't
>> work well when climbing a big hill.
>>
>> Noticed this the few times the old clutch would engage on my last trip,
>> too.
>>
>> I'm thinking I need a dual alternator pulley and belts but if it's the
>> fan clutch making the belts squeal then it's not an Alternator problem.
>> It's the water pump pulley that is squealing, no? And that already HAS
>> two belts on it.
>>
>> Time for new belts? They might have 10,000 miles on them. Maybe 6
>> years old. Didn't keep good records of when I replaced them last.
>> Still look to be in great shape.
>>
>> What say ye?!
>>
>> Kelvin
>> '73 23'
>> _______________________________________________
>> GMCnet mailing list
>> List Information and Subscription Options:
>> http://temp.gmcnet.org/cgi-bin/mailman/listinfo/gmclist
>>
>>
> _______________________________________________
> GMCnet mailing list
> List Information and Subscription Options:
> http://temp.gmcnet.org/cgi-bin/mailman/listinfo/gmclist
> _______________________________________________
> GMCnet mailing list
> List Information and Subscription Options:
> http://temp.gmcnet.org/cgi-bin/mailman/listinfo/gmclist
>
>
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| Re: [GMCnet] New Fan Clutch and noisy belts... [message #96434 is a reply to message #96430] |
Thu, 19 August 2010 13:27 |
Ken Burton
Messages: 10030
Registered: January 2004
Location: Hebron, Indiana
Karma: 10
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Senior Member |
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Replace the belts with the CORRECT WIDTH 7/16" belts. This means DO NOT USE NAPA or GATES. NAPA and Gates belts say 7/16" but are really 3/8" belts.
Go to AutoZone and get Kelly-Springfield, or Duralast, or Goodyear belts. They are cheap and are the correct width.
Duralast is made by Kelly-Springfield which is a brand owned by Goodyear.
To determine if you have a true 7/16" (11mm) belt take a 10 mm open end wrench with you to the store. If the 10 mm. wrench fits over the belt you are buying then the belt is too thin.
Ken Burton - N9KB
76 Palm Beach
Hebron, Indiana
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| Re: [GMCnet] New Fan Clutch and noisy belts... [message #96438 is a reply to message #96437] |
Thu, 19 August 2010 14:14 |
bhayes
Messages: 263
Registered: March 2010
Karma: 1
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Senior Member |
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I just read this snippet on the gmcmotorhome.info FAQ regarding the dual alternator pulley:
"The belts are the stock Gates belts currently recommended by Cinnabar. I am using two Gates XL-7570 (3/8" x 57-5/8") belts for the alternator and one Gates XL-7619 (3/8" x 62-1/2") belt for the A/C compressor."
Are the Gates belt recommendations incorrect?
Bryan Hayes
'76 Eleganza II
Salt Lake City, Utah
Bryan Hayes
'76 Eleganza II
Salt Lake City, Utah
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| Re: [GMCnet] New Fan Clutch and noisy belts... [message #96445 is a reply to message #96430] |
Thu, 19 August 2010 15:34 |
George Beckman
Messages: 1085
Registered: October 2008
Location: Colfax, CA
Karma: 11
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Senior Member |
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| KRDietz wrote on Thu, 19 August 2010 10:11 |
But the batteries were totally charged (just unplugged the coach before
driving it) so the Alternator wasn't even working to speak of. The belt
wasn't slipping on the alternator pulley Theoretically the water pump
pulley was slipping with the fan clutch engaged. And that WP pulley
already has two belts driving it.
Don't think there would be any help with dual alternator belts.
|
I agree. Dual alternator pulleys will only keep the alternator from squealing and you are getting the squeal when the fan clutch comes on. It is slipping at the water pump.
I don't want to subtract from the importance of belts being wide enough and not running down in the pulley from wear. Another issue is tightening sequence. The power steering belt must be done first. Once the alternator belt is tight you can't get the PS to move enough. You might check. I noticed the PS had gotten looser than the alternator on my coach. It is such a short little guy, it is hard to get it equally tight. Don't pry in the tank of the PS pump as it is made out of tinfoil.
I have had some success working underneath, using a bar that will fit between the water pump pulley and the PS pulley. My bar actually rode in the pulley grove of the PS. The trouble is you need about three hands to tighten the PS pump while you pull on the bar and check the tension. I suppose this is why guys make belt tighteners.
'74 Eleganza, SE, Howell + EBL
Best Wishes,
George
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| Re: [GMCnet] New Fan Clutch and noisy belts... [message #96446 is a reply to message #96407] |
Thu, 19 August 2010 15:44 |
C Boyd
Messages: 2629
Registered: April 2006
Karma: 18
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Senior Member |
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| Kelvin Dietz wrote on Thu, 19 August 2010 11:39 |
Installed an Autozone 92-2797 fan clutch last night. Seems to work ok
with the testing I could do. Only 83° but I have a nice, steep test
hill. It got fully engaged a few times.
The problem is that when it does engage the belts start squealing like
crazy. Backing off the gas a bit makes the squeal stop but that doesn't
work well when climbing a big hill.
Noticed this the few times the old clutch would engage on my last trip, too.
I'm thinking I need a dual alternator pulley and belts but if it's the
fan clutch making the belts squeal then it's not an Alternator problem.
It's the water pump pulley that is squealing, no? And that already HAS
two belts on it.
Time for new belts? They might have 10,000 miles on them. Maybe 6
years old. Didn't keep good records of when I replaced them last.
Still look to be in great shape.
What say ye?!
Kelvin
'73 23'
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GMCnet mailing list
List Information and Subscription Options:
http://temp.gmcnet.org/cgi-bin/mailman/listinfo/gmclist
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Kelvin: The Auto Zone 92-2797 is the Sevier duty that Ken Burton said was noisy. I believe it turns more RPM because it was harder to turn in my hand. This is probably your issue. Getting new belts would be your best bet in the long run.
In my previous posts; I have the Auto Zone 92-2747 Heavy Duty. I like it for cooling and low noise level. The 92-27705 is the standard duty that the original GM part # crossed to..
C. Boyd
76 Crestmont
East Tennessee
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| Re: [GMCnet] New Fan Clutch and noisy belts... [message #96449 is a reply to message #96445] |
Thu, 19 August 2010 16:03 |
C Boyd
Messages: 2629
Registered: April 2006
Karma: 18
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Senior Member |
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I have had some success working underneath, using a bar that will fit between the water pump pulley and the PS pulley. My bar actually rode in the pulley grove of the PS. The trouble is you need about three hands to tighten the PS pump while you pull on the bar and check the tension. I suppose this is why guys make belt tighteners.[/quote]
Sir: (from the bottom) there is a cast on "bracket pry lug" on the front pump housing behind the pully (not the tank) that is there for prying against. From the book...
BELT ADJUSTMENT
When adjusting a power steering pump belt,
never pry against the pump reservoir or pull against
the filler neck. To increase belt tension move the
pump outward by prying against the bracket pry lugs
or against the pump housing casting extension directly
behind the pump drive pulley .
C. Boyd
76 Crestmont
East Tennessee
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| Re: [GMCnet] New Fan Clutch and noisy belts... [message #96461 is a reply to message #96456] |
Thu, 19 August 2010 20:23 |
 |
ljdavick
Messages: 3548
Registered: March 2007
Location: Fremont, CA
Karma: -3
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Senior Member |
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I just picked up a set of belts from my local shop and they were perfect.
Oh, wait. My local shop is Applied GMC :~)
Larry Davick
Fremont, California
The Mystery Machine
'76 (ish) Palm Beach
----- Original Message -----
From: "Matt Colie" <mcolie@chartermi.net>
To: gmclist@temp.gmcnet.org
Sent: Thursday, August 19, 2010 3:50:21 PM
Subject: Re: [GMCnet] New Fan Clutch and noisy belts...
emerystora wrote on Thu, 19 August 2010 16:17
> On Aug 19, 2010, at 1:14 PM, Bryan Hayes wrote:
> > I just read this snippet on the gmcmotorhome.info FAQ regarding the dual alternator pulley:
> >
> > "The belts are the stock Gates belts currently recommended by Cinnabar. I am using two Gates XL-7570 (3/8" x 57-5/8") belts for the alternator and one Gates XL-7619 (3/8" x 62-1/2") belt for the A/C compressor."
> >
> > Are the Gates belt recommendations incorrect?
> >
> > Bryan Hayes
> I would not recommend that you use the 3/8" Gates belts. The Gates belts used to be 7/16" but they no longer are.
>
> Emery Stora
> 77 Kingsley
> Santa Fe, NM
I'm not at all sure what is going on here.
I just bought 7570 and 7612 belts. Both are marked as 13/32 (10mm) and measured at 0.0422 (bigger than 10mm, but still smaller than 7/16). Maybe I got old stock?
Matt
--
Matt & Mary Colie
'73 Glacier 23 Chaumiere (say show-me-air)
SE Michigan - DTW 3.2/4R
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Larry Davick
A Mystery Machine
1976(ish) Palm Beach
Fremont, Ca
Howell EFI + EBL + Electronic Dizzy
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| Re: [GMCnet] New Fan Clutch and noisy belts... [message #96476 is a reply to message #96449] |
Fri, 20 August 2010 00:34 |
George Beckman
Messages: 1085
Registered: October 2008
Location: Colfax, CA
Karma: 11
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Senior Member |
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| C Boyd wrote on Thu, 19 August 2010 14:03 |
Sir: (from the bottom) there is a cast on "bracket pry lug" on the front pump housing behind the pully (not the tank) that is there for prying against. From the book...
BELT ADJUSTMENT
When adjusting a power steering pump belt,
never pry against the pump reservoir or pull against
the filler neck. To increase belt tension move the
pump outward by prying against the bracket pry lugs
or against the pump housing casting extension directly
behind the pump drive pulley .
|
Thanks. I will look for that little puppy next time.
'74 Eleganza, SE, Howell + EBL
Best Wishes,
George
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| Re: [GMCnet] New Fan Clutch and noisy belts... [message #96520 is a reply to message #96407] |
Fri, 20 August 2010 13:02 |
Bob de Kruyff
Messages: 4260
Registered: January 2004
Location: Chandler, AZ
Karma: 1
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Senior Member |
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""Time for new belts? They might have 10,000 miles on them. Maybe 6
years old. Didn't keep good records of when I replaced them last.
Still look to be in great shape.
""
Kelvin-I just recently went thru the same thing and installed the severe duty clutch as well as new belts. My Autozone no longer carries the belts under the Kelley brand but apparently now sells the same ones under the Duralast brand. Also, I found several conflicting belt numbers between the various sites and previous posts. Finally I just told them to look up the numbers that they show for the Toronado (78 in my case) and installed them. All of them fit correctly and are the correct width as well and rediculously inexpensive. Also, the fan or water pump pulley counts on all three belts to drive it and all three need to be tight. I am running the standard single groove alternator pulley, however, it is a new machined pulley that came with the rebuilt alternator I installed a few years ago. The old stamped pulleys do wear over time. I suspect sometimes people resort to a double pulley when a new single groove pulley will be just fine for another 25 years.
Bob de Kruyff
78 Eleganza
Chandler, AZ
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| Re: [GMCnet] New Fan Clutch and noisy belts... [message #96567 is a reply to message #96481] |
Fri, 20 August 2010 17:16 |
Ken Burton
Messages: 10030
Registered: January 2004
Location: Hebron, Indiana
Karma: 10
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Senior Member |
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Just go to Autozone and tell them you want 5 of those belts. They will have them in the next day. Then compare the lot numbers on the five and choose two that match. Return the other three.
Ken Burton - N9KB
76 Palm Beach
Hebron, Indiana
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| Re: [GMCnet] New Fan Clutch and noisy belts... [message #97264 is a reply to message #96407] |
Thu, 26 August 2010 07:11 |
Rick Williams
Messages: 256
Registered: July 2004
Karma: 0
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Senior Member |
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I was in Green Bay yesterday so I stopped at an Auto Zone. I do not have one in my area. A Duralast 15560 alternator belt for my '78 403 was wide enough. I used the 10mm wrench method. The PS belt was not wide enough. I do not remember the part number. I think it was 15540 but I am not sure. I did not look at an AC belt.
Rick
Rick Williams
Bliss, Michigan
1978 Eleganza II
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