2018 Grand Design Momentum

On the driver side of the 2018 Momentum Toy Hauler cracked in two locations above the center leaf spring holder. This issue occurred on May 1, 2025. While pulling out of a shop after having the leaf spring holders replaced the axle traveled through a small depression on the ground causing the frame to flex and make a loud enough sound to be heard in the truck pulling the camper. While investigating the situation it was discovered that the frame cracked at the weld points of the gusset bracket that was attached to the frame. The owner of Hawkeye Diesel Repair and two mechanics were on-site during the issue. [XXX] , the mechanics, and the owner of the RV inspected the frame as soon as the sound happened. It was discovered that the new leaf spring holders were firmly connected to the frame but the frame had cracked. The RV has been parked at in their parking lot since. INFORMATION REDACTED PURSUANT TO THE FREEDOM OF INFORMATION ACT (FOIA), 5 U.S.C. 552(B)(6)

I am writing to formally report a series of serious structural concerns we are experiencing with our Grand Design Momentum 349M fifth wheel/toy hauler, which appear to be related to excessive frame flex/failure or upper deck instability. These issues began toward the end of last year and have progressively worsened, raising significant safety concerns for our family. The following symptoms have been observed: * Bay and Propane Doors Opening During Transit Both the bay door and propane doors on either side of the trailer have opened unexpectedly while towing on the highway, posing a major safety hazard. * Loud Cracking Sounds from Front Driver’s Side Wall We consistently hear loud cracking noises from the front driver’s side wall during towing and hitching, suggesting structural stress or movement. * Exterior Trim Separation The exterior trim pieces repeatedly separate during travel, despite multiple attempts to re-secure them with bolts. * Cabinetry Movement in Front Cap Sleeping Area Most concerning, the cabinetry in the front cap—where our 8-year-old son sleeps—visibly shifts forward and backward during towing and hitching. This movement is both alarming and unacceptable from a safety standpoint. We have documented these issues with photos and video evidence, which are enclosed with this message. Please ensure the volume is turned up when reviewing the video to hear the structural noises clearly. Regards, --- [XXX] Email: [XXX] Phone #: [XXX] INFORMATION REDACTED PURSUANT TO THE FREEDOM OF INFORMATION ACT (FOIA), 5 U.S.C. 552(B)(6)

I started noticing rub marks on the interior walls next to the night stands after the last few uses, and they appear to be getting worse after each use. I was made aware of the deck/frame flex issues the some GD fifth wheels are having and was referred to TSB 24-001. My RV is experiencing the exact concern described in the TSB. I opened a case number with GD, and took the RV to an authorized repair center. The repair center took measurements and confirmed my deck flex concern with GD and recommended a complete replacement/repair of the structural material and hardware. GD denied the claim! They only authorized replacement of the Lag Screws only, with larger lag screws per the TSB. In reviewing the TSB I don’t see how this fixes the problem! It only provides a temporary bandaid to the deck flex issue which will return after the next couple of uses. (The repair facility agrees that is a possibility). How does installing a larger fastener into an already compromised material provide a permanent repair? From what I’ve seen, the material it’s being screwed into is only 1” x 1”. Drilling a larger hole and installing a 1/2” dia. screw doesn't seem to leave much material left for structural integrity. Since GD has denied a complete and proper structural repair, I could only hope that this Deck Flex issue doesn't come back worse, resulting in an accident while traveling causing an injury or fatality. Being the original owner of this RV, I expected better customer support from Grand Design.

Structural Frame Failure. We found frame damage at a rest stop while traveling down the interstate. We observed side wall separations and multiple cracks in the welds around the pin box. The 5th wheel trailer was taken to a commercial truck frame repair shop in Florida and after opening up the panel underneath the pin box we discovered multiple breaks/cracks in the structural frame. We filed and insurance claim and an adjuster came out and photo documented all the frame damages along with documenting the overall build construction of the frame. The insurance company denied the claim primarily due to “manufacturing defects” and they clearly documented this in their report. We attempted to repair the visible damage to the frame. However, we suspected there was likely additional frame damage behind the walls and front cap which we could not visually see without removing. This was not done due to the large expense required just to remove and insurance and the manufacture denied our claim. We have discovered that there are many other people who have or are experience the exact same frame issues we have experienced and decided to file a claim with NHTSA as a result since the manufacture is denying any liability except for new units within their 2 to 3 year manufacture limited frame warranty. Our 5th wheel was only about 5 years old when frame failure occurred.

We have frame failure on our trailer, we have not taken it apart yet to give all the details on the welds broken but metal is starting to come out from the fiberglass, and our cabinets inside came part. We contacted Grand Design and they stated as second owners there is no warranty, we contacted Lippert they said to reach out to GD and our insurance said they do not repair manufacturing issues. We will be taking to a shop at the end of February and will have a better understanding of all the issues.