cab fiberglass bulge

John,
I looked at your pictures an it is hard to tell if you have the problem. Put your head / eye at the side turn signal light in the trim strip and look straight back to the rear. The strip should be straight (not sticking out) from rear to the front. There is a slight curve in at the front near the light.
--
Ken Burton - N9KB

76 Palm Beach

Hebron, IN
 
Ok I'll do that in the morning and post the photos

john

----- Original Message -----
From: "Ken Burton"
To:
Sent: Wednesday, April 13, 2005 10:36 PM
Subject: Re: [GMCnet] cab fiberglass bulge

>
>
> John,
> I looked at your pictures an it is hard to tell if you have the problem.
> Put your head / eye at the side turn signal light in the trim strip and
> look straight back to the rear. The strip should be straight (not
> sticking out) from rear to the front. There is a slight curve in at the
> front near the light.
> --
> Ken Burton - N9KB

> 76 Palm Beach

> Hebron, IN
>
>
 
John,

From your picture, it does appear that your driver side has the bulge just
like mine. I am going to take pictures tonight with a straight edge to
highlight this area. The bulge/flare does start exactly at the body-to-cap
seam forward but I can't tell whether it actually starts at the body molding
line or from the bottom of the window.

I wasn't following the thread closely because at the time I didn't think it
was relevant to me but as I understand it, we think the bulge is NOT part of
the design and is caused by the front frame clip slipping upwards? My unit
has 160,000 miles on it.

Mark Wall 76 E2 (with middle age spread but I still like the look)
 
http://www.gmcmhphotos.com/gallery/showalbum.php?uuid=jharper&aid=1018

----- Original Message -----
From: "Ken Burton"
To:
Sent: Wednesday, April 13, 2005 10:36 PM
Subject: Re: [GMCnet] cab fiberglass bulge

>
>
> John,
> I looked at your pictures an it is hard to tell if you have the problem.
> Put your head / eye at the side turn signal light in the trim strip and
> look straight back to the rear. The strip should be straight (not
> sticking out) from rear to the front. There is a slight curve in at the
> front near the light.
> --
> Ken Burton - N9KB

> 76 Palm Beach

> Hebron, IN
>
>
 
> -----Original Message-----
>...
> was relevant to me but as I understand it, we think the bulge is NOT part of
> the design and is caused by the front frame clip slipping upwards? My unit
> has 160,000 miles on it.
>
> Mark Wall 76 E2 (with middle age spread but I still like the look)

Mark,

That's not how I interpret Gene Tucker's analysis of the problem. His position
is that the front cap's just hanging out there with no real support forward of
the first circumferential rib. That is, it receives no significant support from
the frame, including through the forward struts. He wants to correct that.

Take a kraft paper grocery bag (or visualize doing so), cut out one of the short
sides, then hold the bag horizontal by gripping the rim of the two long sides
with the open side down. You've now got an approximation of the shape of the
front cap and you'll see that the sides bow out (or maybe in). What Gene's
proposing is analogous to gluing a couple of yardsticks to the center of the two
sides so they'll have to stay straight.

Now we need to consider the effects of making that rigid connection. Gene
mentioned nothing detrimental resulting from it, but I'm not so sure. If there
is indeed significant movement of the front frame, then that will be transmitted
into the fiberglass, rather than somewhat isolated as it is now. Is that good
or bad? I'm not sure. To me it seems possible that other problems may arise:
Loosening of the cap-to-main body joint? Increased distortion of the windshield
and window openings?

I really have no idea -- just speculating/brainstorming. Now that it's a matter
of interest, the bulges will probably stick out like a sore thumb and I'll be
forced to decide which way to swing. For now I've got enough other projects to
distract me.

Ken H.
 
Are you sure? Are there any coaches that don't have this bulge?

john

----- Original Message -----

The strip should be straight (not sticking out) from rear to the front. .
> --
> Ken Burton - N9KB

> 76 Palm Beach

> Hebron, IN
>
>
 
> http://www.gmcmhphotos.com/gallery/showalbum.php?uuid=jharper&aid=1018
>
> **SNIP **


Forget the bulge, I'll take your beautiful coach.



On the bulge, your driver's side looks great. You passenger side has a slight bulge. That is reverse of mine which had both sides bulged out with my drivers side being much worse.



The budging causes a problem is a few inches below the trim strip is were the floor of the coach meets the side wall. This is where you get all of the air leaks while running down the road. Also as the fiberglass end cap starts to squat down the front grill area becomes malformed. Then you have cracking of the grill and other things.



Thank you for the pictures. They sure point out that the cap was strait at one time.



I have a question. Could this bulging be caused by collapsed body isolators. Mine are in bad shape and I have not got around to replacing them yet.



Ken B.


--
Ken Burton - N9KB

76 Palm Beach

Hebron, IN
 
Ken,

I'm getting ready for a fishing trip so its bad timing for me to take a lot
of photos, but next week is good. I think the difference you see in the
photo between right and left side is the way the camera was set. They both
look the same when eye balled. I've previously checked my front body pads
and they look fine to me. I can photo them next week. I don't understand
what in the photos makes you say "they sure point out that the cap was
straight at one time". As far as air leaks I haven't noticed any but will be
paying attention this weekend while on the road. I'll definitely have that
checked on both sides.

john

----- Original Message -----
From: "Ken Burton"
To:
Sent: Thursday, April 14, 2005 10:24 AM
Subject: Re: [GMCnet] cab fiberglass bulge

>
>

>> http://www.gmcmhphotos.com/gallery/showalbum.php?uuid=jharper&aid=1018
>>
>> **SNIP **
>

> Forget the bulge, I'll take your beautiful coach.

>

> On the bulge, your driver's side looks great. You passenger side has a
> slight bulge. That is reverse of mine which had both sides bulged out
> with my drivers side being much worse.

>

> The budging causes a problem is a few inches below the trim strip is were
> the floor of the coach meets the side wall. This is where you get all of
> the air leaks while running down the road. Also as the fiberglass end cap
> starts to squat down the front grill area becomes malformed. Then you
> have cracking of the grill and other things.

>

> Thank you for the pictures. They sure point out that the cap was strait
> at one time.

>

> I have a question. Could this bulging be caused by collapsed body
> isolators. Mine are in bad shape and I have not got around to replacing
> them yet.

>

> Ken B.

>
> --
> Ken Burton - N9KB

> 76 Palm Beach

> Hebron, IN
>
>
 
Front grill. No, no damage other than the clips breaking and the PO using
screws directly through the grill to hold it in place.

john

----- Original Message -----
From: "Ken Burton"
To:
Sent: Thursday, April 14, 2005 10:24 AM
Subject: Re: [GMCnet] cab fiberglass bulge

>
>

>> http://www.gmcmhphotos.com/gallery/showalbum.php?uuid=jharper&aid=1018
>>
>> **SNIP **
>

> Forget the bulge, I'll take your beautiful coach.

>

> On the bulge, your driver's side looks great. You passenger side has a
> slight bulge. That is reverse of mine which had both sides bulged out
> with my drivers side being much worse.

>

> The budging causes a problem is a few inches below the trim strip is were
> the floor of the coach meets the side wall. This is where you get all of
> the air leaks while running down the road. Also as the fiberglass end cap
> starts to squat down the front grill area becomes malformed. Then you
> have cracking of the grill and other things.

>

> Thank you for the pictures. They sure point out that the cap was strait
> at one time.

>

> I have a question. Could this bulging be caused by collapsed body
> isolators. Mine are in bad shape and I have not got around to replacing
> them yet.

>

> Ken B.

>
> --
> Ken Burton - N9KB

> 76 Palm Beach

> Hebron, IN
>
>
 
Ken,

It doesn't seem to me that collapsed body-frame isolators would contribute much
to the bulges we see at the sides of the front cap. If the the main isolators
become lower than the front strut donuts, wouldn't that tend to lift the front
of the cap, making it narrower instead of giving the middle age spread we see?

Of course, the more I try to think the whole thing through, the more I realize I
don't know what's happening. To follow the line of reasoning above, I'd expect
the frame to sag in the middle, at the splice, raising the front of the cap,
causing it to be narrower still.

Hmmm. Wonder how many sides of this issue I've taken now. Hope no one's
keeping count. :-)

Ken H.

> -----Original Message-----
> From: owner-gmclist [mailto:owner-gmclist] On Behalf Of
> Ken Burton
>...
> I have a question. Could this bulging be caused by collapsed body isolators.
> Mine are in bad shape and I have not got around to replacing them yet.

>

> Ken B.

>
> --
> Ken Burton - N9KB

> 76 Palm Beach

> Hebron, IN
 
No bulging on ours

Greg
73 23 Canyon Lands

> [Original Message]
> From: j harper
> To:
> Date: 4/14/2005 1:54:13 PM
> Subject: Re: [GMCnet] cab fiberglass bulge
>
> Are you sure? Are there any coaches that don't have this bulge?
>
> john
>
> ----- Original Message -----
>
> The strip should be straight (not sticking out) from rear to the front. .
> > --
> > Ken Burton - N9KB

> > 76 Palm Beach

> > Hebron, IN
> >
> >
>
>
 
Well I'll be !! Thats a very good album. Do you have any photos of where the bolts go through the side from the outside? The bolts that pull the bulge in. I assume?? that those bolts would go through where the exterior trim strip is, right? Does he cut them off and leave them or remove them after the glues/adhesives dry?

john

----- Original Message -----

For anyone that wants to see what Gene Tucker did to fix the coach we saw at GMCES Lake Park, I just posted some photos I took of the fix. from what I got out of his talk. Gene was trying to block out the hot and cold air that was passing through this space to help heating and cooling as much as to fix the bulge.

http://www.gmcmhphotos.com/gallery/showalbum.php?uuid=rotor&aid=1019

http://tinyurl.com/7ywf8

Richard Sowers
74 Sequoia
Fayetteville, NC
 
Hey Ken, here ya go this looks like a good easy fix!!!

john
----- Original Message -----

For anyone that wants to see what Gene Tucker did to fix the coach we saw at GMCES Lake Park, I just posted some photos I took of the fix. from what I got out of his talk. Gene was trying to block out the hot and cold air that was passing through this space to help heating and cooling as much as to fix the bulge.

http://www.gmcmhphotos.com/gallery/showalbum.php?uuid=rotor&aid=1019

http://tinyurl.com/7ywf8

Richard Sowers
74 Sequoia
Fayetteville, NC
 
From: "Ken Henderson"

> Of course, the more I try to think the whole thing through, the more I
realize I
> don't know what's happening.

Ken,

Is it possible that a little bow in both sides near the front is normal?
Has anyone ever seen a "straight" front with absolutely no now?

Bob Sobrito
La Mesa, Ca
77 Kingsley, 455.
 
> -----Original Message-----
> From: owner-gmclist [mailto:owner-gmclist] On Behalf Of
> Bob Sobrito
>...
> Has anyone ever seen a "straight" front with absolutely no now?

Let's see, when was that...'78?

KH
 
Bob,

Greg Jankowski says

"No bulging on ours

Greg
73 23 Canyon Lands"

----- Original Message -----
>
> Is it possible that a little bow in both sides near the front is normal?
> Has anyone ever seen a "straight" front with absolutely no now?
>
> Bob Sobrito
> La Mesa, Ca
> 77 Kingsley, 455.
>
>
>
 
> -----Original Message-----
> From: owner-gmclist [mailto:owner-gmclist] On Behalf Of
> Bob Sobrito
>...
> Is it possible that a little bow in both sides near the front is normal?
> Has anyone ever seen a "straight" front with absolutely no now?

One more thought: I think most of us are pretty well agreed that middle-aged
spread accounts for the beltline pulling away from the cabinets at the door.
And that the weight on the roof is probably largely responsible for that: a few
hundred pounds jumping up & down on the roof a few thousand times per mile
probably does cause some flattening of the tube we ride around in.

Maybe the front cap bulges are more due to flattening of the front rib hoop than
to isolator settling, frame flexing, etc.

Again, is pulling the sides in and securing them to the floor really going to
cure a symptom without attacking the cause? And will there be unwonted side
effects? I dunno...

Ken H.