Home » Public Forums » GMCnet » My door closes easier now!!
|
|
|
|
| Re: My door closes easier now!! [message #127632 is a reply to message #127630] |
Fri, 27 May 2011 09:38   |
Andrew
Messages: 213
Registered: April 2011
Location: Connecticut
Karma: 0
|
Senior Member |
|
|
Interesting. I wonder if you could have achieved the same fix by jacking the frame rails (a fraction of an inch) at just the right place.
I don't know enough to compute where that place would be... 350 extra lbs of engine block, X feet aft of the effective bogie fulcrum, lifting Y lbs of the front portion of the coach (center of gravity probably a few feet aft of the engine), modified by the bending strength of the 35-yo frame rails...
I guess I'd guess five-ish feet forward of the bogies?
It would be easy to test on a poor-closing coach, though you've probably have to overjack it a bit and leave it for a while to make it "permanent".
And I'd worry about the reversing stresses over time..probably the sag would return more quickly (some fraction of 35 years  ).
Fascinating though.. Hope it sticks!
[EDIT: Of course the math above doesn't matter -- if it's a frame sag issue, then the sag point will be the weak spot in the frame rails if there is one, or the levered center of gravity if there isn't. Bouncy road stresses will concentrate there (assuming consistent loading...and modified by the suspension factors), and that's the place to "correct" them...right?]
1973 Sequoia 260 (since 2011)
[Updated on: Fri, 27 May 2011 09:44] Report message to a moderator |
|
|
|
|
|
| Re: My door closes easier now!! [message #127639 is a reply to message #127637] |
Fri, 27 May 2011 11:38 |
Andrew
Messages: 213
Registered: April 2011
Location: Connecticut
Karma: 0
|
Senior Member |
|
|
But the only added weight was in the back, right?
I was assuming the weight on the tongue would lever the frame on the rear suspension and push the middle up, just a little. No?
1973 Sequoia 260 (since 2011)
|
|
|
|
| Re: My door closes easier now!! [message #127641 is a reply to message #127637] |
Fri, 27 May 2011 11:55 |
 |
gordh1
Messages: 332
Registered: February 2011
Karma: 0
|
Senior Member |
|
|
Don't confuse the chassis with the body frame, and also don't think that x pounds working on the rear section of the chassis frame (where you will find 2 main body frame mounts), wouldn't have some significant effects... 
I have most of Scruffy's plywood floor out now and the cabin frame floor beams have all taken on a rise of about a half-inch or more in the middle. The cabin frame overhangs the chassis by about 8 inches each side, so it's *really* loading up things in curious ways.
It appears too, 73 and 74 models had a lot less floor cross beams than later flavors, especially between the bogies (i.e. *none*). I have the interior gutted and windows and door out right up as far (back to front) as the door. The bend is really substantial.
Plan is, the 1/2" rubber strips are going. The left side was pretty good, the right, squished to nothing. After that, I'm going to add some gusseted angles off the side of the real frame only at the points of the body frame beams - and attach (properly fasten) the body frame to these, bringing the floor down to flush with the real frame and removing the interior body floor beams.
GM obviously built 'part one' to drop on to 'part two' and had to compromise (or adjust) to be able to do so. It should be interesting to see if and how the cabin and chassis can assist each other in making a more sound 'unit'.
If the weight on the back it twisting the coach body up (we could be talking nothing dimensions here), well, I don't doubt it could twist or torque all the way to the front.
Gord
|
|
|
|
|
|
| Re: [GMCnet] My door closes easier now!! [message #127683 is a reply to message #127641] |
Fri, 27 May 2011 19:09 |
 |
USAussie
Messages: 15912
Registered: July 2007
Location: Sydney, Australia
Karma: 6
|
Senior Member |
|
|
Gord,
I'm not sure if I've got this right but do you intend to bolt the aluminum
body frame to the steel chassis?
Regards,
Rob M.
USAussie - Downunder
AUS '75 Avion - The Blue Streak TZE365V100428
USA '75 Avion - Double Trouble TZE365V100426
-----Original Message-----
From: gmclist-bounces@temp.gmcnet.org
[mailto:gmclist-bounces@temp.gmcnet.org] On Behalf Of Gord H
Sent: Saturday, May 28, 2011 2:55 AM
To: gmclist@temp.gmcnet.org
Subject: Re: [GMCnet] My door closes easier now!!
Don't confuse the chassis with the body frame, and also don't think that x
pounds working on the rear section of the chassis frame (where you will find
2 main body frame mounts), wouldn't have some significant effects... ;)
I have most of Scruffy's plywood floor out now and the cabin frame floor
beams have all taken on a rise of about a half-inch or more in the middle.
The cabin frame overhangs the chassis by about 8 inches each side, so it's
*really* loading up things in curious ways.
It appears too, 73 and 74 models had a lot less floor cross beams than later
flavors, especially between the bogies (i.e. *none*). I have the interior
gutted and windows and door out right up as far (back to front) as the door.
The bend is really substantial.
Plan is, the 1/2" rubber strips are going. The left side was pretty good,
the right, squished to nothing. After that, I'm going to add some gusseted
angles off the side of the real frame only at the points of the body frame
beams - and attach (properly fasten) the body frame to these, bringing the
floor down to flush with the real frame and removing the interior body floor
beams.
GM obviously built 'part one' to drop on to 'part two' and had to compromise
(or adjust) to be able to do so. It should be interesting to see if and how
the cabin and chassis can assist each other in making a more sound 'unit'.
If the weight on the back it twisting the coach body up (we could be talking
nothing dimensions here), well, I don't doubt it could twist or torque all
the way to the front.
Gord ;)
--
Scruffy 74 Canyonlands :) Use the forum - it's easy!
http://gmc.mybirdfeeder.net/GMCforum/index.php?t=thread&frm_id=1
_______________________________________________
GMCnet mailing list
Unsubscribe or Change List Options:
http://temp.gmcnet.org/cgi-bin/mailman/listinfo/gmclist
_______________________________________________
GMCnet mailing list
Unsubscribe or Change List Options:
http://temp.gmcnet.org/cgi-bin/mailman/listinfo/gmclist
Regards,
Rob M. (USAussie)
The Pedantic Mechanic
Sydney, Australia
'75 Avion - AUS - The Blue Streak TZE365V100428
'75 Avion - USA - Double Trouble TZE365V100426
|
|
|
|
| Re: [GMCnet] My door closes easier now!! [message #127685 is a reply to message #127683] |
Fri, 27 May 2011 19:36 |
|
gordh1
Messages: 332
Registered: February 2011
Karma: 0
|
Senior Member |
|
|
| Robert Mueller wrote on Fri, 27 May 2011 20:09 |
Gord,
I'm not sure if I've got this right but do you intend to bolt the aluminum body frame to the steel chassis?
|
Hi Rob,
Yes I do. Using caution of course with the dissimilar metals, some triangulation to the real frame, and then strengthening the body frame. It should basically become a unibody and if my math is right, the strength of the structure should improve dramatically.
The original wood and aluminium floor will be history - only about 8 or so inches of the floor beams will remain on each side attached to fabricated angles along the frame, then the new floor skinned level and attached to both real frame and body frame, using 1/4" aluminium, and attached every few inches.
Questions, comments, curses of course welcome - and wagers as to how long it takes to pop the windows out on these wonderful Quebec roads? 
|
|
|
|
| Re: My door closes easier now!! [message #127687 is a reply to message #127630] |
Fri, 27 May 2011 20:00 |
|
|
Hard to argue with results and it worked!
John
| Larry wrote on Fri, 27 May 2011 07:03 |
Motor has been off of the carrier now for a month since we got home and door is still closing just fine....GO FIGURE!!
|
John Ruff
Chandler, AZ
1975 Eleganza
WA3RIG
If I use ZDDP in a new car - will the tappets go flat?
|
|
|
|
| Re: My door closes easier now!! [message #127735 is a reply to message #127662] |
Sat, 28 May 2011 09:38 |
Larry C
Messages: 1168
Registered: July 2004
Location: NE Illinois by the Illino...
Karma: 0
|
Senior Member |
|
|
I noticed a similar thing last week when working on the rear brakes. With the rear passenger side on jack stands, my door closes MUCH easier and has a more even seam when closed.
A small amount of flex will make a noticeable impact on a tolerance like the door adjustment. I wouldn't be surprised if you could repeat this by parking on an uneven surface.
______________________________________________________________
Ok so if we suspect the frame has sagged a bit, and we all know the body sagged with the mid life body bulge, we could try something???
Ok how about when the camper is parked, jack up the hitch and see if there is improvement in the door. ( the door closing has been an issue for a long time on mine ). If it indicates the body tension improves the door operation, then perhaps leaving the back end supported over storage periods might help correct the sag?????
Wow we could any where with this, what a find.
Gatsbys' CRUISER  08-18-04
74 GLACIER X, 260/455-APC-4 Bagg'r
Remflex Manifold gaskets
CampGrounds needed, Add yours to "PLACES" />
http://www.gmceast.com/travel
_
|
|
|
|
| Re: My door closes easier now!! [message #127795 is a reply to message #127735] |
Sat, 28 May 2011 15:16 |
 |
mike miller
Messages: 3576
Registered: February 2004
Location: Hillsboro, Oregon
Karma: 0
|
Senior Member |
|
|
| Larry C wrote on Sat, 28 May 2011 07:38 |
.. Ok so if we suspect the frame has sagged a bit, ...
... Ok how about when the camper is parked, jack up the hitch and see if there is improvement in the door. ...
|
If the body has "sagged a bit," jacking on the hitch would make the problem worse. (The original poster says _adding_ weight to the hitch _helped_ his door.) Now if your coach had been used to pull a heavy trailer and the frame had torqued the other way, your solution has merit.
Mike Miller -- Hillsboro, OR -- on the Black list
(#2)`78 23' Birchaven Rear Bath -- (#3)`77 23' Birchaven Side Bath
More Sidekicks than GMC's and a late model Malibu called 'Boo'
http://m000035.blogspot.com
|
|
|
|
| Re: My door closes easier now!! [message #127819 is a reply to message #127795] |
Sat, 28 May 2011 18:28 |
Larry C
Messages: 1168
Registered: July 2004
Location: NE Illinois by the Illino...
Karma: 0
|
Senior Member |
|
|
Yes, sorry, I figured that out after I hit ENTER...
Just strange and a pleathura of thoughts come to mind of what might have happened to have corrected, if that is what happened, the problem.
If the body "OLD AGE BULGE" happened because of frame flex, can you just imagine what is going on when weight is added to the rear and the frame is shifting again????
If it would be that simple to fix the bulg, how great would that be. These old girls are subject to twists and bends just like any other frame and even more so since their life has been expanded 2 to 3 times normal vehicle service. WOW
WOW
Gatsbys' CRUISER 08-18-04
74 GLACIER X, 260/455-APC-4 Bagg'r
Remflex Manifold gaskets
CampGrounds needed, Add yours to "PLACES" />
http://www.gmceast.com/travel
_
|
|
|
|
Goto Forum:
Current Time: Thu Sep 26 16:53:19 CDT 2024
Total time taken to generate the page: 0.01126 seconds
|
GMCforum
Search
Help
Register
Login
Home
