2021 GRAND DESIGN MOMENTUM Unknown Or Other Problems

I am experiencing symptoms, consistent with excessive frame movement and structural failure in my 42 foot fifth wheel toy hauler RV. We have been monitoring this for the time we have owned it just over six weeks and have noticed an increase and symptoms that research shows indicate there is a problem.. we are seeking professional inspection and guidance to establish the scope of it and hopefully catching it at the earlier side in order to hopefully deal with the issue easier than after a total failure. The symptoms include 1- the interior upper section horizontal lag bolts that hold the camper walls to the frame all had come loose completely. There were four on one side and five on the other. 2- the underside curved fillon panel by the pin box is ripple and curved, and shows movement 3- the left and right sides of the camper towards the front are becoming out of square with the rest of the camper and the seals around the doors are showing larger gaps and looking more out of square 4- interior doors and exterior doors of the camper are all experiencing difficulty latching and are becoming out of square to the original structure 5- there is a changing of the distance, measurements both in height, and in relation to the lower frame members from the pin box where the camper tows from. And what appears to be some twisting out of square. 6- front panel door is buckling in the center and will no longer close geometry of the opening has been compromised It is clear that we are experiencing frame structural failure between the area where the camper toast from in relation to the main frame of the camper

FRAME FAILURE AND STRUCTURE. CARGO DOOR OPENED WHILE TRAVELING. (SAFETY ISSUE) FURNITURE SEPARATING FROM STRUCTURE. BROKEN OVERHEAD CABINETS OVER BED (SAFETY ISSUE) WALL SEPARATING FROM FLOOR IN CARGO AREA WOOD DUSTING FROM CEILING IN BEDROOM AND GARAGE AREA.

We took possession of our new 2021 Grand Design 381M fifth-wheel travel trailer in April 2021. During 2021 and 2022, the trailer saw minimal road use. However, during our travels, we observed significant movement within the trailer, and on several occasions, the cargo bay doors opened while in transit. In August, we contacted Grand Design due to visible interior damage and abnormal movement. They arranged to pick up the trailer and transport it to their facility for inspection and repair. Grand Design confirmed that the trailer had suffered a frame failure. They reportedly completed the necessary repairs and returned the trailer to us. Unfortunately, not all issues were resolved. In May 2023, the trailer was returned to the facility for additional repairs. Afterward, it was returned to us once again. In August 2024, signs of frame failure reappeared. We contacted Grand Design, and a mobile technician was dispatched to inspect the trailer. The technician confirmed another instance of frame failure. Due to seasonal considerations, we arranged for the trailer to be transported back to Grand Design in March 2025. Repairs were made, and the trailer was returned later that month. We remain deeply concerned about the adequacy and durability of the repairs, and whether the trailer is truly roadworthy and safe. Despite multiple requests, Grand Design has not provided any photos of the frame damage or documentation of the repairs performed. This lack of transparency is especially troubling given the recurring nature of the issue and the broader concerns surrounding frame integrity across multiple Grand Design models. We are left with the impression that the structural integrity of our trailer—and potentially others—has been compromised. We believe this poses a serious safety risk for anyone traveling on U.S. roadways.

Excessive frame flexing/failure in the upper deck of our 5th wheel.discovered damage is 1. Sawdust on furniture in the bedroom and by entry door from living area to the garage at intersection of wall and floor. 2. Furniture rub marks on wall in bedroom from upper cabinets with driver side having bowed out base or molding where it sits on window valance. 3. Separation of night stands from wall in bedroom on both sides and a curved wall in front.  4. Squeaky floor in bedroom on drivers side between bed and closet 5. Wrinkles and separation from steps and wall in the upper deck 6. Wrinkles around frame of hallway window in upper deck 7. Exterior of RV underneath the nose along where pin box is located there is separation with screws coming loose/out. The outside cap moldings loose and flapping in the breeze while going down the road 8. Lag bolts in the front section of 5th wheel that hold the wall to the frame some were missing, some coming loose, and all were undersized. These issues can contribute to further frame cracking and king pin failure that may result in significant property damage or even death, putting our family and others on our highways at risk. Grand Design sent a service repair technician (SRT) to inspect. During inspection a crack in the frame was found and told that welding would be needed. Appointment made at authorized repair facility and now the needed repair is being denied due to the pin box movement is at their minimum tolerance, yet the frame failure still exists causing a safety concern. Grand Design is aware of frame failure in several models and has yet to issue a recall of the structural defects caused by under sizing the frames and using the wrong lag bolts, and denying the repairs that are covered under their extended 5 year frame warranty.

I am experiencing upper deck frame flex which our manufacturer has unsuccessfully attempted to repair twice (Nov 2021 and Oct 2024). The manufacturer refuses to accept responsibility for our safety concerns and has ceased all remaining repair attempts which was communicated to us through emails. This excessive flex causes my cargo doors to open while traveling, damage to the supporting frame structures (frame cracks throughout), and the attaching king pin that no longer supports the weight of our RV as evidenced by the 1 inch drop when hooking our RV up to the tow vehicle. Multiple repair attempts have been made by the manufacture at the manufacturer's facilities however, each attempt has failed and is simply weakening the already weakened frame. The manufacturer has extended the warranty to its consumer base however, my contention is this is merely "optics" given their refusal to apply a "permanent" fix to our RV that IS currently under their extended warranty.

After a trip we noticed that when we had the rv connected to the truck, the front closet would not close. There was also cracking on the nose cover of the rv. We (my wife and I) had a problem with the cargo doors and entry doors coming open on other trips and lost stuff on the highway so we talked to the rv dealer to get a frame inspection. what was found was that the frame was broke in a few places and the door side wall of the camper was not attached. We have also had the rear spring hanger break the year before while driving almost pulling me out of the lane I was traveling in. The camper is sitting at the dealers now because it cannot be towed, and the dealer will not weld the frame due to liability. missing and broken bolts in the frame and body were also discovered.

Main doors coming open - currently bungee cording , cargo doors coming open - currently bungee cording, slides coming out a couple inches, leaf spring broke during travel on interstate, open case with Grand Design since January 22, 2023, case # 00621051 and Grand Design has not been helpful in addressing these issues. An RV tech confirmed frame flex symptoms: sawdust from nose of rv in interior, furniture rubbing on walls moving bac and forth, broken cabinets coming out of ceiling, missing screws.

Excessive frame flex in pin box area of fifth wheel. Forward left cargo door unlatching while towing. Vehicle is currently at Lazydays dealer in TN for inspection and TSB for excessive frame flex. Inspection has revealed major structural cracks and structural failure in upper deck steel frame structure. Vehicle has been deemed unsafe to transport and must be repaired in place or partially repaired for transport to factory. We noticed excessive deformation of the pin box and substantial rubbing of internal cabinets, etc upon return from a recent trip. Based of the damage, it would have been possible for the RV structure to separate from our tow vehicle putting us and others on the road at significant risk of injury or death. We saw indications of interior movement of cabinets and rubbing on walls for several thousand miles, but no indication of significant pinbox deflection until recently. Manufacturer has provided no guidelines or communication to owners to be aware of potential problems or to indicate things to look for that may indicate the vehicle poses a serious risk/hazard. Initial signs of rubbing inside the vehicle, and a loose latch and flapping of cargo door were observed in January 2024. We have video of substantial gap opening and movement of interior cabinets when taking vehicle off of stabilizer jacks and loading onto fifth wheel hitch of truck. Unable to get additional pictures currently as the RV is at the dealer for repairs. Will attempt to get photos of internal frame damage early next week if possible.

Side compartments opening while towing unit on highway…items in compartment flying out …hatches won’t closed properly to much gap…big gap also on top cap where it connects to wall in front..unit taken to lazdays Tampa for frame flex recall…inspection revealed major cracks in frame everywhere as a result causing major frame flex…lots of welding is being done…by grand design mechanic ..slide system also damaged as a result of frame flex …unit is currently still at lazdays Tampa being welded together…they keep finding more and more damage …. You guys should send an inspector to inspect it to see major frame damage from poor frame build I believe unit is unsafe to be roadworthy with the amount of welding and repairs to frame the keep doing

Due to excessive frame flex, multiple welds have broken and the trailer walls are coming apart from the main frame. Vehicle is currently in for repair, but if the hitch had broken while towing, or if the walls had completely separated while towing, the result would have been a serious, and potentially fatal, accident.

The frame and suspension on our 2021 Grand Design is failing. The frame on the upper deck has broken welds and there is visible movement in the upper deck when hitching and unhitching. The furniture inside the main bedroom move when hitching and unhitching. The side walls have started to detach from the frame as evidenced by screws backing out or breaking. The suspension has bent components. The frame is also bending in the right front. The hitch visibly moves into the upper deck when hitching.

I had noticed the Pin Box flexing, especially over bumps or any rough road or bridge approach. As it got worse I could tell we a lot of flex in the frame area where the Pin Box is located. I contacted the dealer and they examined our RV and determined the frame was flexing due to the bolts connecting the chassis to the actual frame of the RV body being to small and working loose/broke. The dealer replaced the bolts with larger bolts and advised the flex is now within specifications. It is better but it's not great by any means. I'm concerned as the RV gets older the condition will get worse and could even become hazardous. This condition has already affected the value of the RV and when it's out of warranty I'll have no recourse other than to fix it myself.

Frame failure! Driving down the road and noticed the kin box moving up and down into the Rv! I do not feel comfortable towing this Rv I feel it is going to cause a serious accident.

5th wheel with frame flex issues. Compartment doors and entry/exit doors open while traveling down the road. The underlying issue is frame flex.

Our frame is showing signs of excessive flex, when we hook up our trailer to the tow vehicle.

There was excessive frame Flexing in the nose section of our 5th wheel. I inspected the lag bolts in the front section of our 5th wheel that hold the wall to the frame and found 4 bolts missing of the 12 that are supposed to be installed. Also, the bolts that were installed were undersized. I also have damage to the inside wall and cabinets from over-flexing during travel. I have not contacted a dealer of the manufacturer but have been following many other individuals on forums who have had similar issues. I have not had my unit inspected yet, but plan to start the process with Grand Design. The warnings were trim pieces falling off after travel days and damage to the interior wall. I also replaced screws on the outside cap that loosened, and some fell out.

Our 5th wheel RV has had frame flex (frame failure) 4 separate times. The manufacturer has "fixed" it 3 times unsuccessfully. We have just owned this for 3 years and due to the length of time in between reporting to the manufacturer and waiting for repairs, the RV has been broken more than not during ownership. The pinbox is currently flexing due to broken welds on the frame and causes interior and exterior damage to the unit each time it is towed.

In february 2023 we noticed several internal (sawdust, exposed finish nails, floor noises, broken trim, pinched wall coverings) and external (multiple locked doors opening in transit)signs that our RV frame was experiencing excessive flexing, more than what is expected and necessary for a nearly 42' metal vehicle frame. The frame has since failed, the suspension is underrated for the weight of the vehicle. The manufacturers UVW and GVWR sticker knowingly contained incorrect OEM information with proof from a CAT scale leading to me as the owner believing the vehicle could have been loaded with more OEM item weight from the manufacturer than what was accounted for and annotated. Despite understanding the allowable weights and keeping this RV well under the advertised GVWR, the 6 separate leafsprings of the suspension are all flattened. The upper deck frame failed under normal on-road (and very little) use. A 2024 TSB was issued on my RV for "upper deck flex". .5" of movement at the pin box was the "within limits" passing grade. My unloaded and empty RV's measurement taken by an authorized service center by the manufacturer in keeping with the TSB, measured 1.5" of flex at the pin box. This failure was so great it led to the manufacturer instructing the Service center to not move it or release it to me out of safety concerns. It has been at the service center since 4/10/2024 ti present without any instruction or communication from the manufacturer on how to proceed either under warranty or otherwise.

Signs of frame flex/failure Lag boats through frame beam into exterior walls, are protruding and coming out. Countertop and cabinet, rubbing against the walls, lots of cracks in the Front Cap. The RV as less then 5000 miles on it and only used maybe once a month during summer months. Per my research these are signs of frame flex/failure.

We have a 2021 Grand Design 353G Momentum fifth wheel RV. We have experienced frame failure with the upper deck of the RV. It has been inspected and repaired by the manufacturer recently, but I wanted to let you know about this issue that seems to be prevalent in the RV industry. It seems that the manufacturer has under engineered the chassis that Lipper has produced for them. I feel that this repair will not be sufficient for the life of the RV. I believe this is extremely unfair due to the cost of these and the cost my wife and I have incurred during this ordeal. Frame failures seem to be at the forefront of issues currently and things need to change. We saw signs of failure up to a year before we had it repaired but did not know what we were dealing with. The welds on the chassis are poor and the quality control of these units are very, very poor. If these were to fail on the highway, lives are at risk.

Frame failure causing the vehicle to be unsafe to tow given the failure is in the PIN area. If the PIN box fails that could cause a catastrophic accident resulting in great harm or death to the driving public. Grand Design has failed to take full ownership of this issue with 100's of their large 5th wheel. On inspection welds are weak or missing leading to these RV's becoming unsafe to tow down the road. While GD has approved some work to remediate the broken welds, it's minimum effort and not a full fix. It will still be unsafe to tow with root cause in their upper deck walls not being addressed.

Frame Failure: Welds broke, and walls separated. The dealer and manufacturer acknowledged the issue and repaired the issue.

The pin box is flexing to the point that its damaging the inside of the RV. I made various videos and provided them to the manufacturer. Based on the movement and damage the unit should not be moved until it has a professional inspection. Its possible that I have frame flex due to broken welds. The Manufacturer has asked it to be towed to a dealer for further inspection. I do not feel safe to do so in fear if it fails completely and causes damage or injury to others. Local dealer does not perform any repairs or inspection of structural damage.

It is a common issue with the Grand Design Momentum G-class travel trailers where the interior floor and possibly the frame are flexing so much that is causes the laminate flooring to lift and separate from the plywood underneath. Bubbles in my laminate flooring were found during our initial walk through when our trailer was purchased, I was lead to believe that it was just a simple adhesive issue, but have since found from research that this is a common issue with all the g-class trailers. Many people on the Grand Design facebook pages have experienced the same exact issue, in the same exact areas as mine. Several have had them "repaired" to find out that the problem reoccurs. I am truly concerned about the structural integrity of the trailer as I believe that if the frame is flexing to this extent, that there is a lot of potential for it to become a catostrophic failure in the future while traveling down the road, putting myself and others in potential danger. Metal can fatigue and crack over time from being flexed. Bluedog RV (Portland, OR) has seen this issue several times, and has helped customers get their trailers repaired by a company called Fibrenew. I have e-mails from Bluedog confirming that they know a problem exist, but they claim they do not have anyone capable of fixing it, and do not know of anyone who can fix it. Fibrenew no longer is willing to do the repairs as they feel they can not adequately repair them, and they believe it is a structural integrity issue caused by Grand Design engineering. Our trailer was recently taken to Bluedog RV to have this fixed, but it is unknown what they did. The bubbles in our flooring still exist so it is my belief that they did nothing. It has never been inspected by anyone else. Files attached with file names 1,2 and 3 are of my trailer. The other files attached are supporting documents.

We had a towing incident chain's came detached from camper one side was only tack welded when contacted grand design got no where with them