2021 GRAND DESIGN MOMENTUM Complaints

Frame flexing issues. Storage compartment doors opening while towing and loosing belongings.

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 contact owns a 2021 Grand Design Momentum 397 Fifth Wheel. The contact stated that there were tears in the metal of the subframe. While driving at unknown speeds, the RV was bouncy. After connecting to a truck and towing the truck, the RV became unsteady. The local dealer was not contacted. The RV was not diagnosed or repaired. The manufacturer was contacted and referred the contact to the frame manufacturer. The contact called the Lippert manufacturer and was informed about measuring the distance of the subframe. The failure mileage was unknown. The VIN was not available.

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.

This trailer has frame flex in the gooseneck area to the point it is damaging the cabinetry in the front of the trailer. I have been in multiple momentum trailers with this problem and the dealership just wants me to trade it in or charge an astronomical amount of money to try and fix. It’s a known problem that everyone needs to be aware of.

This is in addition to safety report #11540112. While further inspecting the trailer, the right rear shackle bolt was also found to be broken in half. The spring was still on, but it was probably working its way out, which would have cause the same failure as the left side, in the original report.