Major structural issue

Likes to tow

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Joined
Mar 17, 2009
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474
Location
Huntington, WV
Rear Wall moving side to side causing a bulge in the skirt at the bottom of the trailer on both sides of the trailer. I replaced the skirt section behind the slide before we left on this trip and now it's bulged or bent again!! Doing research on the Internet and discovered this bad news!!
I suggest watching all three videos and this is exactly what has happened to me and apparently many other Grand Design owners. I'm currently on the road and will have to come up with fix or solution when we return. What a shock!!!!!
 
I removed the sofa to expose where the rear wall and floor make contact. They used 1/2 inch thin wall aluminum angle to fasten the back wall to the floor. The screws spaced 8 inches apart were all in the floor but all the screws into the back wall were gone!! The reason they were gone is there was no metal behind the thin wood. Screws simply worked out of the thin wood and were laying everywhere under the sofa. This apparently was the only way the back of the trailer was held in place. A youtube search has revealed that more than just Grand Design has experienced this failure of the rear wall wagging left to right as you roll down the highway. It had moved far enough to bulge the lower trim skirt on the outside.
 
No! Since my unit is a 2017 and there was only a 3 year structural warranty I decided to forego a fight with Grand Design. I have fixed it myself and feel very confident it is much better than when it rolled off the assembly line. I removed the sofa and put very heavy 2x3 inch iron angle screwed to the floor and found the metal inside the rear wall approximately 2 inches above the floor level which was where the screws were designed to go. The little 1/2 inch angle they used was not tall enough to allow the screws to penetrate anything but the lauan wood. No wonder the screws fell out. I also went underneath the trailer and fabricated bracing from the lower part of the rear wall to the trailer hitch mounting brackets. My trailer came with a 2 inch receiver for a hitch so there was plenty of strong structure to bolt to. I think the rear wall now is very secure and will not wag as I go down the road!!
 
Sounds like a good repair - and I assumed that your had a newer unit like the one in the video you posted - missed your pic that makes it obvious though.
 
I believe I have the same issue, I took out the rear couch and put a small desk workstation there, and found the small 3/4 screws all over the floor.
I also have some 3/4” angle tie ing the wall and floor together. I was thinking to put some larger angle in place of the small angle and fasten it to the aluminum studs in the wall. I really don’t want my back wall to start coming apart…..
 
I was hoping to tap into the aluminum square tubing wall studs but soon realized that a 3 inch flat aluminum bar went all the way across the back wall about 2 inches off the floor. Why not screw into that about every 5 inches? So I dug around in my shop for a piece of 2x3 steel angle and used the 3 inch side up against the wall. That way I could use self tapping metal screws and run all across the back. Why didn't Grand Design just lower this 3 inch wide bar to floor level and use larger screws and maybe a heavy duty angle like I did? This is simply poor engineering or poor assembly. Looks like whoever was doing this job on the assembly line would point out the fact they were putting screws into Lauan and not metal !!!! Just plain and simple poor quality product which cost the consumer tens of thousands of $$. I will never buy another RV !! This is my third 5th wheel. I'm going back to a home built truck camper if I can convince my wife. I doubt she will agree. But I know I can build a quality product. I wish someone would come up with a kit so you could build your own RV. Engineering may design a product but the assembly is where it all goes down the toilet !!
 
I was hoping to tap into the aluminum square tubing wall studs but soon realized that a 3 inch flat aluminum bar went all the way across the back wall about 2 inches off the floor. Why not screw into that about every 5 inches? So I dug around in my shop for a piece of 2x3 steel angle and used the 3 inch side up against the wall. That way I could use self tapping metal screws and run all across the back. Why didn't Grand Design just lower this 3 inch wide bar to floor level and use larger screws and maybe a heavy duty angle like I did? This is simply poor engineering or poor assembly. Looks like whoever was doing this job on the assembly line would point out the fact they were putting screws into Lauan and not metal !!!! Just plain and simple poor quality product which cost the consumer tens of thousands of $$. I will never buy another RV !! This is my third 5th wheel. I'm going back to a home built truck camper if I can convince my wife. I doubt she will agree. But I know I can build a quality product. I wish someone would come up with a kit so you could build your own RV. Engineering may design a product but the assembly is where it all goes down the toilet !!
 
Thanks for this thread. You guys got me looking at my trailer today. So far so good but I’ll keep an eye on it. My previous trailer didn’t even have the angle iron. Just a wood trim piece nailed in along the bottom. I could see day light through it since the nails pulled out.

This one looks mostly secure but I can’t see behind the end tables without taking stuff apart. I’ll hit all the screws to be sure they’re tight. One looks to be backed out a little.
 

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Screws going into the Lauan panel will certainly not hold tight for long. There needs to be some aluminum tubing or metal on the other side of the Lauan wood and screws long enough to penetrate the metal. This is all that holds the back wall to the floor. Like shown in the video the wall can move back and forth while you are underway!! Hard to believe something like this is sold to the public with no penalty to the manufacturer.
 
Even more ridiculous that on my last trailer they didn’t really even bother to fasten it to floor. At least not in between either side. Just a thin piece of wood trim for cosmetics. I’m sure it was fastened on the ends, up the walls etc or after 5 years and thousands of miles I’d have had issues. So, GD at least did more than that manufacturer.

Thanks again for the heads up. I’ll add this to the periodic inspection list.
 
On our SOB trailer, I have had this happen. I also had the screws along the back wall vertical trim either loosen, strip or come out. I had read somewhere that there is some kind of wind force pulling the rear wall out as the trailer is barreling down the Highway. To address that, installed some beefier screws and strapping metal to the bottom of the wall to the bottom of the floor (exterior) to secure it…the rear wall no longer pulls outward.

The vid above was helpful for me to understand where the dimples on the J-wrap came from. At the time, I was not so much concerned about the dimples but rather watching the side wall bulge when the slides went out.

The side walls have 3” screws going up through the floor into the wall along the length of the trailer. Those in the affected areas were sheared. I suspect the slide was being pushed out too far….particularly where there are two slides a couple feet apart…both pushing the wall out. I got some beefy TEK screws and installed them along the wall, resealed, reinstalled J-wrap.
 

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