[GMCnet] Belt Tensioner

[Tom Whitton]

Is anyone making an alternator belt tensioner for the GMC Motorhome - something similar to the automatic tensioners on late model vehicles? I have new belts on our coach and have them tensioned to the best of my ability but still sometimes have belt squeal for a short time after start-up.

Tom Whitton
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[gene Fisher]

read here
http://www.gmcmhphotos.com/photos/data/5950/KEEP_THEM_STRAIGHT.pdf
and here
http://www.gmcmhphotos.com/photos/data/5950/GMC_BELTS_WILL_NOT_LET_YOU_DOWN.pdf
and here
http://www.gmcidiotsguide.com/joomla/component/hikashop/category/14-belttensioners

gene

--
Gene Fisher -- 74-23,77PB/ore/ca
“Give a man a fish; you have fed him for today --- give him a URL and
-------
http://gmcmotorhome.info/
Alternator Protection Cable
http://gmcmotorhome.info/APC.html

[George Rudawsky]

JimK has a belt tensioner for sale on his web-site if you want one. It looks like the one pictured in Gene's links.

If the belt only squeals for a bit at start up, it may not be that big of a problem?
--
George Rudawsky
Chicago, IL
75 Palm Beach

[Billy Massey]

And it's the real one. Professionally built with hardened parts.
http://www.appliedgmc.com/prod.itml/icOid/1107
and, also available
http://www.appliedgmc.com/prod.itml/icOid/1359

bdub

-----Original Message-----
From: On Behalf Of George Rudawsky
Sent: Saturday, February 09, 2013 5:12 PM

JimK has a belt tensioner for sale on his web-site if you want one. It
looks like the one pictured in Gene's links.

If the belt only squeals for a bit at start up, it may not be that big of a
problem?

[Jim Kanomata]

Tom,
The spring loaded units are designed for Serpentine belts that are flat and
thin with a wrap around the alternator and A/C compressor.
On V belts they are the ones that you set y turning the bolt and locking it
down with a nut.

--
Jim Kanomata
Applied/GMC, Fremont,CA
ji...@appliedairfilters.com
http://www.appliedgmc.com
1-800-752-7502

[gene Fisher]

remember

what ever you use to set the belt tension (a 2x4 - or a tensioner ;>)
the bolts in the device (alternator, ac pump, ps pump) are what hold the
belt tight, not the tensioning device. the device can even be removed
after
the belt tension is complete.....
http://www.gmcmhphotos.com/photos/data/5950/KEEP_THEM_STRAIGHT.pdf

and

the most critical part is , the alignment of the belt leaving the pulley
and using the correct belt as well as the tension.

gene

On Sat, Feb 9, 2013 at 3:53 PM, Billy Massey <bd...@wtconnect.com> wrote:

--
Gene Fisher -- 74-23,77PB/ore/ca
“Give a man a fish; you have fed him for today --- give him a URL and
-------
http://gmcmotorhome.info/
Alternator Protection Cable
http://gmcmotorhome.info/APC.html

[Matt Colie]

Mr ERFisher wrote on Sat, 09 February 2013 20:06
> <snip>
> http://www.gmcmhphotos.com/photos/data/5950/KEEP_THEM_STRAIGHT.pdf
> <snip>
> gene

Gene,

Where did you come up with the nice picture of the dual belt installation?
Can you tell us the part number that relates to the picture's 0315?
And, thanks for the specs on how to build the belt jack.

Thanks,

Matt
--
Matt & Mary Colie
'73 Glacier 23 Chaumière (say show-me-air) Just about as stock as you will find
SE Michigan - Twixt A2 and Detroit

[gene Fisher]

> Can you tell us the part number that relates to the picture's 0315?
>

what is this?

gene

--
Gene Fisher -- 74-23,77PB/ore/ca
“Give a man a fish; you have fed him for today --- give him a URL and
-------
http://gmcmotorhome.info/
Alternator Protection Cable
http://gmcmotorhome.info/APC.html

[Matt Colie]

Mr ERFisher wrote on Sun, 10 February 2013 11:56

> > Can you tell us the part number that relates to the picture's 0315?
> >
> what is this?
>
> gene
> --
> Gene Fisher -- 74-23,77PB/ore/ca
>

Gene,

In your link:
http://www.gmcmhphotos.com/photos/data/5950/KEEP_THEM_STRAIGHT.pdf
On the bottom left of side 6 is a picture of 455 belts.
It has all the parts called out by number, but there is no picture/part number reference included.
Can you tell us the part number that relates to that picture's part 0315?

Thank You

Matt
--
Matt & Mary Colie
'73 Glacier 23 Chaumière (say show-me-air) Just about as stock as you will find
SE Michigan - Twixt A2 and Detroit

[Tom Whitton]

Appreciate the suggestions on the belt tensioner, particularly the one from Gene advising, "whatever you use to set the belt tension (a 2x4 - or a tensioner ;>) the bolts in the device (alternator, ac pump, ps pump) are what hold the
belt tight, not the tensioning device." That makes sense. Belts do elongate. To compensate, spring loaded tensioners come out now on most new vehicles. My other "tinker toy" is a 25-year old '88 Fiero GT. Fieros did not have automatic tensioners installed at the factory. Similar to the GMC, you can set the tension on the alternator belt and it might not be long before the belt starts squealing again. Here's the retrofit I installed to solve the problem: http://home.windstream.net/dodgerunner/Fiero1_files/BracketInfo.html
It's not a big deal but apparently, nothing similar is available for our motorhomes.
Tom Whitton

[Jim Kanomata]

Tom,
I'm telling you it will not work unless you have a flat belt.

--
Jim Kanomata
Applied/GMC, Fremont,CA
ji...@appliedairfilters.com
http://www.appliedgmc.com
1-800-752-7502

[George Rudawsky]

I seem to remember that some folks were experimenting with serpentine belt conversions (ie using 'flat' belts), but I seem to remember that they didn't work out very well.

Perhaps someone has revisited this, but I think properly sized and tensioned belts should continue to work, and the available screw type tensioner designs should make setting the belt tension a bit easier.

--
George Rudawsky
Chicago, IL
75 Palm Beach

[Ken Henderson]

George,

Bobby Moore, JR Slaten, and I have put many, many miles on serpentine belt
arrangements. None of us have had any significant problems. Leigh
Harrison sold quite a few conversion kits. Some of his customers had
overheating problems because of running the water pump backward. The 3 of
us never did, but when Leigh designed and had reverse flow pumps
manufactured, I ran some of the prototypes. The first two had problems,
one of which put me beside the road in NC. He fixed those and provided me
with a final version which I never installed. Later he found a production
reverse-flow pump, which I understand he now uses.

When I replaced the 455 with the Cad500, I designed a 2-serpentine belt
system which has worked perfectly for me. By using two belts I was able to
drive the water pump in the correct direction. I would NOT like to go back
to V-belts, especially with the current narrow belt problems.

Ken H.
Americus, GA
'76 X-Birchaven w/Cad500/Howell EFI+ & EBL
www.gmcwipersetc.com

On Mon, Feb 11, 2013 at 2:18 PM, George Rudawsky wrote:

>
>
> I seem to remember that some folks were experimenting with serpentine belt
> conversions (ie using 'flat' belts), but I seem to remember that they
> didn't work out very well.
>
> Perhaps someone has revisited this, but I think properly sized and
> tensioned belts should continue to work, and the available screw type
> tensioner designs should make setting the belt tension a bit easier.
>
>

[Tom Whitton]

I really appreciate the input on the automatic belt tensioner. After I sent the picture of the Fiero solution I realized it might be misunderstood because of the flat belt vs. the V-Belts we use. Has anyone tried to fit an automatic tensioner for our V-Belts?

Tom Whitton

[Tom Whitton]

Ken,

Does your flat belt system include an automatic tensioner?

[George Rudawsky]

Glad to hear that folks are having good luck with the serpentine belts, because that seems to be the current wave of the future, and automatic tensioners are nice and the belts are relatively easy to replace. I couldn't remember who had developed the serpentine system, but it was Leigh Harrison.

Now that you mention it, I think it was the water pump issues that I had heard about. Keeping these coaches on the road will continue to require alternatives as original equipment becomes unavailable. For my old Porsches, I have to deal with more and more NLA issues as the manufacturer has little interest in ramping up production for 60 year old models! Luckily, there is a great support system like this one, and independent vendors that are continuing to make seemingly obsolete parts available once again.

--
George Rudawsky
Chicago, IL
75 Palm Beach

[George Rudawsky]

Tom,

After reading Ken's post, I did check Leigh Harrison's website, and it looks like it's a complete kit with everything you need to do the conversion, including a new reversed water pump, heavy duty fan, belt, and a spring loaded GM tensioner. Current price seems to be $1095 for the complete kit.

--
George Rudawsky
Chicago, IL
75 Palm Beach

[Richard Michelhaugh]

WOW, a fellow GMC and Fiero fan!!!

Rick M.

Tom Whitton wrote on Sun, 10 February 2013 18:56

--
1974 26' Canyonlands
aka "The General"
Clinton, TN

[Dan Gregg]

Tom Whitton wrote on Mon, 11 February 2013 17:17

Tom, I doubt it. Don't think it will work with a v belt. But, if you put the adjuster that Jim K. sells that will be end of problem. Fix it once and be done.
To my closest GMC neighbor, who needs to start showing back up in "public"
Dan

--
Dan & Teri Gregg
Dexter, Mo.

http://danandteri.blogspot.com/

[Ken Henderson]

George,

Just to be sure there's no confusion: The serpentine belt Bobby Moore and
JR Slaten developed, a near copy of which I have, was independent of Leigh
Harrison's design.

Ken H.

[Ken Henderson]

Tom,

On the 455, with only 1 belt, yes. On the Cad500 with 2 belts, no.

I don't remember ever seeing an automatic tensioner for a V-belt but don't
see why it wouldn't work. Just remember, if you try to devise one, that
the tensioner must be on a slack side, not one under tension. Preferably
right "after" the driving pulley.

Ken H.
Americus, GA
'76 X-Birchaven w/Cad500/Howell EFI+ & EBL
www.gmcwipersetc.com

On Mon, Feb 11, 2013 at 6:43 PM, Tom Whitton wrote:

> Ken,
>
> Does your flat belt system include an automatic tensioner?
>
>

[Les Burt]

Most garden tractors use a spring loaded tensioner pulley on their v-belt drive system so I don't see any reason why it wouldn't work in an automotive application.

If the tensioner and belt length are carefully chosen, you can increase the pulley wrap, improving contact area and thus reducing slippage.

Les Burt
Montreal

[gene Fisher]

think about it long

Manny took his back off
JimB will not put them on
no gain in performance
turns wp back wards
tends to take out ac pumps
one device problem, and you cannot get home
engine not built for it

just saying, think about why to do it

jwid
gene

--
Gene Fisher -- 74-23,77PB/ore/ca

“Give a man a fish; you have fed him for today --- give him a URL and
-------
http://gmcmotorhome.info/
Alternator Protection Cable
http://gmcmotorhome.info/APC.html

[noi]

Greetings:

Just curious and seeking enlightenment here&#8230;.

Why would an automatic belt tensioner &#8220;NOT&#8221; work with V-Belts?

Thanks for the info!

Carl P.
76 Birchaven
South of Fremont

[Matt Colie]

Ken Henderson wrote on Mon, 11 February 2013 23:57
> Tom,

> I don't remember ever seeing an automatic tensioner for a V-belt but don't see why it wouldn't work. Just remember, if you try to devise one, that the tensioner must be on a slack side, not one under tension. Preferably right "after" the driving pulley.
>
> Ken H.

They do exist, but not in automotive.
They exist where belt lengths are long and replacement is not a serious issue. (Like lawn mower decks.) They have to be placed in the system immediately "up-tension" of the driver so that they are in the lowest tension region of the belt. Many are designed to roll on the back side of the belt which qualifies as "Big Bozo No-No" on the V-belt world as reversing the bend of a belt can severely shorten the life.

Matt
--
Matt & Mary Colie
'73 Glacier 23 Chaumière (say show-me-air) Just about as stock as you will find
SE Michigan - Twixt A2 and Detroit