alternator belt damage

[Ken B]

Jim,
Except in this case it is the top cogs that were coming off of the belt. Why this is happening, I do not know. My thought in this case is to use a
normal belt and see if the problem disappears.
--
Ken Burton - N9KB
76 Palm Beach
Hebron, Indiana

 

[Deb]

Hi Jim. I know that those cogs make it easier on the belt, etc, but since this belt was supposedly the right size, and the cogs were ripping off,
until I can figure out what's wrong (like Matt said, I will be looking at the alternator alignment) I'm going to try to stick with something more
sturdy(?) in case I am unsuccessful at getting that alternator properly aligned (IF that's the problem).

I suspect that the belt is not actually 0.44" like it says in the description (15575 & 15570 supposedly the same) since it does look like it's sitting
low in the pulley. But that may also be due to unreasonable wear because of....? I'll know better when I get out there later to measure it up.
Or maybe the pulley itself is worn. Who knows. Was really sick last night, so I think I don't need to be sticking my head upside down in the engine
hatch just now
--
Deb McWade
Logan Lake, BC, CAN
"Li'l Sister"
'77 Kingsley, 403, EBL EFI;
TZE167V101404
It's Bigger on the Inside!

 

[Ken B]

> Jim,
> Except in this case it is the top cogs that were coming off of the belt. Why this is happening, I do not know. My thought in this case is to
> use a normal belt and see if the problem disappears.

That is sit. This one is the same thing that I used only in Kevlar.

On your Dayco part number, please understand that the number system is used by many manufacturers, including Goodyear, Gates, etc. It is simply the
size in their code. 15 says it is 7/16" wide, 570 says it is 57.0 inches OUTSIDE Circumference.

On the A55 belt it is a different type of belt and measured differently. The A says 1/2" wide and the 55 says it is 55.0 inches INSIDE circumference.
While not mentioned in the part number, the 55.0" inside size will be 57.0" outside circumference.

So once you find the correct numbers for the PS and AC belts it will be a simple to put together the A type belt number by simply subtracting 2 and
rounding to the closet one available. I am not where I can look up those numbers right now but someone here will do it for you.
--
Ken Burton - N9KB
76 Palm Beach
Hebron, Indiana

 

[Deb]

Found the corresponding dimensions for the AC (A43; GM9433742 comes up as a 45" OC)and PS (A58; GM9422670 an OC of 60") belts. And a Canadian
supplier - a manufacturer in Edmonton actually. Whole order was less than $40 with shipping. Fingers crossed everything works out properly and i can
get these in.

Thanks and I'll keep you posted.
--
Deb McWade
Logan Lake, BC, CAN
"Li'l Sister"
'77 Kingsley, 403, EBL EFI;
TZE167V101404
It's Bigger on the Inside!

 

[Deb]

New belts have arrived. Nothing spectacular, but they look fine. Existing belt is 7/16 (wrench just fits over the belt with no wiggle room to speak
of - metric wrenches are buried under the bench seat). Tension is awful, but that may be from the damage. Or the damage could be from poor tension.
Alignment of the pulleys looks ok by my straight edge.

Hoping it will stop raining long enough for us to get under it and get the belts in. Solid heavy rain for 3 days now and no end in sight. And I have
discovered a leak that has never been evident before. Once the rain stops I can track down the source. I'm pretty sure I know where to start
looking, but won't know till I can get up there.

Hope you all down there are having a good 4th!
--
Deb McWade
Logan Lake, BC, CAN
"Li'l Sister"
'77 Kingsley, 403, EBL EFI;
TZE167V101404
It's Bigger on the Inside!

 

[Deb]

Getting the belts put on tomorrow at a shop that will let me be in there while it's done. Determined that not something we wanted to attempt here at
home. Couldn't get the coach up high enough and I don't have any schematics for the "pathways" for each individual belt. I have seen things straight
down from the top or vice versa from the underside, but not knowing what the front of the engine and pulley system really looks like, I am reluctant
to do this on my own, on my back, for fear of ending up with a coach with 3 belts and no functional pulley systems .

Next question... How long after driving would you expect to have to check & re-tension these?
I read somewhere (on another forum again) that they would run the vehicle (in place) for 15-20 minutes, then check and adjust the tension if needed.
Somehow this doesn't seem like much. Was that time just to allow the belt to seat in the pulleys? How long (time or distance) would you expect to
find that you may have to adjust the tension due to stretching/breaking in that new belt (I assume that there will be some)
--
Deb McWade
Logan Lake, BC, CAN
"Li'l Sister"
'77 Kingsley, 403, EBL EFI;
TZE167V101404
It's Bigger on the Inside!

 

[Jim Hupy]

I always install belts from the open hatch cover. The AC belt lower brace
is easier reached from in front of the right side tire for tightening, but
you must tension it from the top before you tighten the lower brace anyway.
Same with the power steering lower bolt, as well as the lower alternator
bolt. I have replaced belts several thime on the road, and have never
jacked up the coach to do it. But, I have long arms.
Jim Hupy
Salem, Oregon

On Sun, Jul 7, 2019, 1:22 PM Deb McWade via Gmclist
wrote:

> Getting the belts put on tomorrow at a shop that will let me be in there
> while it's done. Determined that not something we wanted to attempt here at
> home. Couldn't get the coach up high enough and I don't have any
> schematics for the "pathways" for each individual belt. I have seen things
> straight
> down from the top or vice versa from the underside, but not knowing what
> the front of the engine and pulley system really looks like, I am reluctant
> to do this on my own, on my back, for fear of ending up with a coach with
> 3 belts and no functional pulley systems .
>
> Next question... How long after driving would you expect to have to check
> & re-tension these?
> I read somewhere (on another forum again) that they would run the vehicle
> (in place) for 15-20 minutes, then check and adjust the tension if needed.
> Somehow this doesn't seem like much. Was that time just to allow the belt
> to seat in the pulleys? How long (time or distance) would you expect to
> find that you may have to adjust the tension due to stretching/breaking in
> that new belt (I assume that there will be some)
> --
> Deb McWade
> Logan Lake, BC, CAN
> "Li'l Sister"
> '77 Kingsley, 403, EBL EFI;
> TZE167V101404
> It's Bigger on the Inside!
>
>
> _______________________________________________
> GMCnet mailing list
> Unsubscribe or Change List Options:
> http://list.gmcnet.org/mailman/listinfo/gmclist_list.gmcnet.org
>

 

[Ken B]

I have never seen a new belt that did not stretch under tension. the 15 or 20 minutes run time check is probably a good idea and then later after a
few hundred miles. The biggest problem checking after 15 or 20 minutes run time is waiting for the engine to cool down. You are working from the top
and a lot of heat will rise up towards you.

Even sitting under tension without running the belts will stretch. Running the engine seems to shorten the stretching process. I had a pair of
double belts one time that did not match. As a test, I hung one double pulley on the wall and suspended 50 pounds a lead shot on another double
pulley. The next time that I checked them several weeks later the shorter belt had stretched to match the longer one. I am sure that actually
running the belt would have shortened the stretching time.

You probably should learn how to install, check, and adjust all three of those belts so you can adjust them after running a few hundred and again
later a few thousand miles. It is not difficult. Finding / knowing what bolts to loosen so you can adjust it is probably the most difficult thing.

Please note. There are three different bolts to loosen the alternator slightly and adjust it. Two are on the top (one is the 4" long pivot bolt and
nut), Plus one more bolt and nut on the bottom front. Reach the bottom one from the top with a ratchet and a medium length extension. Also you will
need a box end to hold the bolt from turning. You need to do it by feel as I am pretty sure that you will not be able to see it at all without a
mirror. It is not difficult to do.
--
Ken Burton - N9KB
76 Palm Beach
Hebron, Indiana

 

[LarryW]

My belt adjustment procedure consists of multiple adjustments. A long time ago an old master mechanic told me that the looser you can run the belt shy
of "squealing", the better off you are. Puts less stress on water pump, alternator and PS pump bearings making them last longer. So, I make a initial
loose adjustment, turn the engine over without spark so it won't start to run the battery down some, so the when the engine does start, the alternator
will be putting out near max. If it squeals after start, I tighten it a little more, and restart. Do this until it does not squeal. Then make minor
adjustment along the way as the belt stretches. This process is relatively work intensive, but IMO is easy on accessories. JWID.
--
Larry
78 Royale w/500 Caddy
Menomonie, WI.

 

[Deb]

> I always install belts from the open hatch cover. The AC belt lower brace
> is easier reached from in front of the right side tire for tightening, but
> you must tension it from the top before you tighten the lower brace anyway.
> Same with the power steering lower bolt, as well as the lower alternator
> bolt. I have replaced belts several thime on the road, and have never
> jacked up the coach to do it. But, I have long arms.
> Jim Hupy
> Salem, Oregon

Thanks for the tips Jim. I'll have to see if my arms are long enough. Never know!
--
Deb McWade
Logan Lake, BC, CAN
"Li'l Sister"
'77 Kingsley, 403, EBL EFI;
TZE167V101404
It's Bigger on the Inside!

 

[Rdenney]

Yes, the top-cog design first came out in 1979 or 1980, as I recall. I was
a mechanic at the time and Dayco advertised them heavily.

I seriously doubt GM “engineered” the belts. I’m sure they used the same
belt specification they had “always” used, and designed everything else
around it. And they did that for the alternator, pumps, and compressor when
those products were first developed, which was well before their
application in the Motor Home. Belt manufacturers then tried to distinguish
themselves in the market with mostly appearance changes while still, as
cheaply as possible, meeting that spec. Width is important (true 7/16”) and
tension. The Goodyear Gatorback is a top-cog design and at least for a
while was a true 7/16” belt.

As to length, alternators and steering pumps in coaches are rarely original
and not all pulleys are exactly the same size. I have trouble getting a
15570 to fit over the pulley without removing the adjustment slot screw
altogether, which is annoying. In one case, I couldn’t get a fresh belt to
fit at all. The only downside to a longer belt is the risk of running out
of adjustment room as the belt wears in.

I’m using the standard 7/16” automotive belts from VBeltSupply and they did
require retensioning within a coupla hundred miles. They seem to be decent.
But when I installed the new engine, I was meticulous about alignment. I
had lots of practice, too—I had to take apart and reassemble that horribly
kludged steering pump bracket three times.

Rick “who has replaced belts from the top in a rainstorm, but a couple of
bolts are easier from the bottom” Denney

On Tue, Jul 2, 2019 at 2:46 PM Jim Kanomata via Gmclist <

> Deb,
> The cog is not that important, the maufactures update the design so dont
> waste your time on these detail . I have seen many years ago where the cog
> was on top to help with flex.
> Tension is more important.
>
>
> --
'73 X-Glacier 230 "Jaws"
Northern Virginia
Offlist email: rick at rickdenney dot com

 

[Deb]

> I have never seen a new belt that did not stretch under tension. the 15 or 20 minutes run time check is probably a good idea and then later after
> a few hundred miles. The biggest problem checking after 15 or 20 minutes run time is waiting for the engine to cool down. You are working from the
> top and a lot of heat will rise up towards you.
>
> Even sitting under tension without running the belts will stretch. Running the engine seems to shorten the stretching process. I had a pair of
> double belts one time that did not match. As a test, I hung one double pulley on the wall and suspended 50 pounds a lead shot on another double
> pulley. The next time that I checked them several weeks later the shorter belt had stretched to match the longer one. I am sure that actually
> running the belt would have shortened the stretching time.
>
> You probably should learn how to install, check, and adjust all three of those belts so you can adjust them after running a few hundred and again
> later a few thousand miles. It is not difficult. Finding / knowing what bolts to loosen so you can adjust it is probably the most difficult thing.
>
>
> Please note. There are three different bolts to loosen the alternator slightly and adjust it. Two are on the top (one is the 4" long pivot bolt
> and nut), Plus one more bolt and nut on the bottom front. Reach the bottom one from the top with a ratchet and a medium length extension. Also
> you will need a box end to hold the bolt from turning. You need to do it by feel as I am pretty sure that you will not be able to see it at all
> without a mirror. It is not difficult to do.

Thanks Ken. I really did want to do this myself. I actually feel bad about wimping out. I am always game to try something when I have something
of a clue about what I'm doing. Or if I have Obi Wan checking over my shoulder. But seeing as I have to know I can be on the road sometime this week
(most likely), I thought I would take it in and get a chance to get a look at it from a more reasonable perspective (standing!). I will have a much
better idea of what I am doing next time around, and I will be able to adjust them in a bit when that time comes along.
--
Deb McWade
Logan Lake, BC, CAN
"Li'l Sister"
'77 Kingsley, 403, EBL EFI;
TZE167V101404
It's Bigger on the Inside!

 

[Deb]

> My belt adjustment procedure consists of multiple adjustments. A long time ago an old master mechanic told me that the looser you can run the belt
> shy of "squealing", the better off you are. Puts less stress on water pump, alternator and PS pump bearings making them last longer. So, I make a
> initial loose adjustment, turn the engine over without spark so it won't start to run the battery down some, so the when the engine does start, the
> alternator will be putting out near max. If it squeals after start, I tighten it a little more, and restart. Do this until it does not squeal. Then
> make minor adjustment along the way as the belt stretches. This process is relatively work intensive, but IMO is easy on accessories. JWID.

I will keep that in mind Larry. Makes sense.. Thanks.
--
Deb McWade
Logan Lake, BC, CAN
"Li'l Sister"
'77 Kingsley, 403, EBL EFI;
TZE167V101404
It's Bigger on the Inside!

 

[Matt Colie]

There is a little snare in our coaches that only 23s that dry camp will ever know about.

The 80 version of a Delco 27SI alternator can actually max out at about 96 amps. (Measured) It is only there for a short time after a cold start with
the house bank down and I bet it only happens to 23s (with the house bank in the front) and it only lasts about a minute - Maybe two. I have never
recreated the event to know if the squeal quits because the load diminishes or the belt gets hot.
100 Amp at 14+VDC is (trust me on this) about the limit of a single belt. (That is almost 2Hp for the alternator alone.)

A double belt can cost you some of the effectiveness of the power steering. I have that mod and when things get wet, the steering can hiccough when
in a very tight maneuver.

So, if it squeals for part of a minute after a cold start, but shuts up soon enough, just remember to check the tension at the next periodic service.

Matt Always carries spare belts
--
Matt & Mary Colie - '73 Glacier 23 - Members GMCMI, GMCGL, GMCES
Electronically Controlled Quiet Engine Cooling Fan
OE Rear Drum Brakes with Applied Control Arms
SE Michigan - Twixt A2 and Detroit

 

[justin brady1]

When we first got our coach on our first long trip we went through like 6 belts.
Basically we would replace they would go for 500 or so miles then start to squeel and then break. Like clockwork.

Finally I wised up and stopped at the 300 mile mark and tightened all the new ones.
Haven't had to replace one since.

Basically when you hear that first hint of a squeel, stop right there and tighten it.
--
Justin Brady
http://www.thegmcrv.com/
1976 Palm Beach 455