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Fan belts [message #81340] Wed, 21 April 2010 13:23 Go to next message
Harry is currently offline  Harry   Canada
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Registered: October 2007
Location: Victoria, BC CANADA
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I was just running up the old machine when the squealing started. I shut it off and saw that the fan/power steering/altenator belt was broke. The altenator does have a two groove pulley. There was only one belt in there. Question is; does one belt run everything? I will be putting two belts back on. How hard is it to do this? Do I just have to slack off the altenator? Thank you for any help.
Re: [GMCnet] Fan belts [message #81349 is a reply to message #81340] Wed, 21 April 2010 15:18 Go to previous messageGo to next message
powerjon is currently offline  powerjon   United States
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David,
The factory layout is a single belt and pulley on the alternator.
You evidently have an alternator that has the double pulley and that's
OK and you can run dual belts, but be sure to match them in length.
Just take the power steering belt off and use two belt for the ps and
alt.
J.R. Wright
On Apr 21, 2010, at 2:23 PM, David H. Jarvis wrote:

>
>
> I was just running up the old machine when the squealing started. I
> shut it off and saw that the fan/power steering/altenator belt was
> broke. The altenator does have a two groove pulley. There was only
> one belt in there. Question is; does one belt run everything? I will
> be putting two belts back on. How hard is it to do this? Do I just
> have to slack off the altenator? Thank you for any help.
> --
> "I've always been crazy, but it kept me from going insane"
> _______________________________________________
> GMCnet mailing list
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J.R. Wright
GMC GreatLaker
GMC Eastern States
GMCMI
78 30' Buskirk Stretch
75 Avion Under Reconstruction
Michigan
Re: Fan belts [message #81352 is a reply to message #81340] Wed, 21 April 2010 15:49 Go to previous messageGo to next message
ljdavick is currently offline  ljdavick   United States
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Registered: March 2007
Location: Fremont, CA
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I just installed the double pulley this last weekend. If you can get the loosened belts between the fan and the shroud then it's a breeze. I had to remove the fan to get the belts on. I removed the fan, loosened the A/C, P/S, and Alternator. Actually I removed the alternator so that I could install the pulley, but you are already there.

You will need a matched set of belts to go around the alternator and the P/S pump. I took the advice of a netter and pushed the P/S pump out as far as possible and cinched it down so that any adjustment to the belts would be done only by the alternator. The reason for this is to allow the belts as much contact area with the P/S pump as possible.

I forgot to install my A/C belt, but who cares - the charge is gone on my system anyway.

Putting the fan back on is a lot of fun. I had to start each nut with only my fingertips. After all that fun I considered cutting a notch in the fan shroud just enough to slide a belt over the fan.

Good luck!


Larry Davick
A Mystery Machine
1976(ish) Palm Beach
Fremont, Ca
Howell EFI + EBL + Electronic Dizzy
Re: [GMCnet] Fan belts [message #81366 is a reply to message #81352] Wed, 21 April 2010 18:43 Go to previous messageGo to next message
USAussie is currently offline  USAussie   United States
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Registered: July 2007
Location: Sydney, Australia
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G'day,

I'm sorry but I'm going to have to disagree with the requirement to get a
"matched" set of belts.

When I installed the double pulley on Double Trouble in September of 2008 I
got two belts from AutoZone. I did not check to see if they came from the
same batch as I didn't know that I needed a matched set.

I fitted them and noticed that one belt was tighter than the other so they
were NOT matched.

I drove Double Trouble for a day or so and when the belt(s) began to squeal
I adjusted them. I drove for a week or so without any squealing but when I
checked them they did take a bit of adjusting.

Since then we have driven over 6000 miles no more squealing or adjustment.
Naturally I will check them as part of my "pre-flight" checks this year when
I get back to the USA.

Bottom line: it appears that the belts stretch / wear to the same point.

I don't know if this will work if / when one belt needs replacement.

Rob Mueller
Sydney, Australia
AUS '75 Avion-The Blue Streak TZE365V100428
USA '75 Avion-Double Trouble TZE365V100426

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Regards, Rob M. (USAussie) The Pedantic Mechanic Sydney, Australia '75 Avion - AUS - The Blue Streak TZE365V100428 '75 Avion - USA - Double Trouble TZE365V100426
Re: Fan belts [message #81386 is a reply to message #81340] Wed, 21 April 2010 21:00 Go to previous message
Harry is currently offline  Harry   Canada
Messages: 1888
Registered: October 2007
Location: Victoria, BC CANADA
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Senior Member
Thank you for all the information. I will dive in to it tomorrow.
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