2020 Grand Design Momentum Problems
Owner-reported complaints filed with NHTSA, grouped by component
Data refreshed
What this page shows
Everything below is an owner-reported complaint submitted to NHTSA about the 2020 Grand Design Momentum, grouped by the component NHTSA recorded on the report. These are not confirmed defects, and they are not recalls. NHTSA does not verify most reports before publishing them, and a category with more reports in it is not evidence that a part is defective.
Complaints are reports submitted by owners and drivers to NHTSA. They are not verified and do not establish that a defect exists.
Reports by component
Ranked by how many owner reports name each component category
- Body & structure1856.3%
- Suspension721.9%
- Interior & seats39.4%
- Electrical13.1%
- Other / unspecified13.1%
- Brakes13.1%
- Tires & wheels13.1%
Percentages are of component mentions. A single complaint can name more than one component, so these do not sum to the total complaint count.
Each component in detail
What the reports in each category say, in the owners' own words
Body & structure
Reports naming the vehicle structure, frame, body panels, doors, hood and trim.
From owner reports, verbatim
I'm submitting this report on our RV because we are discovering we very likely have an issue with the frame which is causing over flexing when it is being towed. This has caused damage inside the RV where the trim and cabinetry are damaging the walls due to more movement than should be occurring. We have notified the manufacturer, Grand Design, for guidance as we've read this could be caused by broken welds in the frame. They requested we send them photos which we have but are still waiting for information back from them. At this point we are concerned that the RV may not be safe to use until we can discuss in more detail the issues we are having and how they can't be fixed if possible. We are aware this is a known issue with this particular model RV. We were told about a TSB that suggested we check to see if the bolts were loose in the front of the unit where the wall and frame meet. We did this and they were loose so we had them replaced with the suggested larger size bolts listed in the TSB. After this was done we monitored the walls to see if we were still getting movement on the walls based on marks we made after the bolt were replaced and unfortunately we still did. Our understanding is the whole front panel of the RV has to be removed so the welds can be inspected and determined if any are broken or compromised and then determine if they can be repaired. Before doing this we want Grand Design to send us information on what to look for. Unfortunately our RV is over the 5 year extended frame warranty they provided so we don't think they will cover the costs although I think there should be compensation if it is determined the frame they used in manufacturing this RV was not strong enough to handle the weight.
My Momentum 5th wheel is experiencing frame flex and wall separation . This condition is causing damage to the interior side wall adjacent to cabinets in the bedroom wall. Frame and or wall assembly is excessively moving in transport and during hooking and unhooking from the unit. Unit will be inspected in the near future by a Grand Design authorized service agents. The condition is further degrading the safety of the unit with each use in transit.
Suspension
Reports naming suspension components — springs, struts, shocks, control arms and related hardware.
From owner reports, verbatim
The contact owns a 2020 Grand Design Momentum RV. The contact stated that while in the process of lubricating the wet bolts of the RV, the contact noticed that the rear-most bolts were missing, and the springs were rubbing against the frame. The mobile technician performed a temporary repair at the residence. The RV was then towed to the dealer, where it was diagnosed. The dealer determined that the spring brackets needed to be straightened and reinforced and needed to be welded inside the brackets. The wet bolts and axle U-bolts and attachments needed to be replaced, the passenger's side and driver's side rear-most tires needed to be replaced. The dealer filed a warranty claim with the manufacturer; however, the claim was denied because the suspension was not covered under the frame warranty coverage. The contact related the failure to NHTSA Action Number: PE24029 (Structure). The failure mileage was approximately 10,000.
Issues with: - original drum breaks failed due to incorrect wiring, requiring 100% assembly replacement. - front wall separation - trim and cabinets moving and separating from walls - missing and broken lag bolts - front weather stripping separated from front cap - excessive sawdust under cabinets after any travel - wallpaper wear showing excessive movement of front bed overhead cabinets during travel - floor joists separating from upper floor - slides opening during travel - leaf spring hangers bending and twisting, and breaking off - spare tire mount failed during highway travel, and spare tire fell off on highway - contacted manufacturer to report in 2024 and they indicated we should self-replace the missing and damaged lag bolts with larger 1/2 inch ones. This was done, and they continue to back out on every trip whether 5 miles or 500 miles.
Too few reports in this category for a page of its own — they appear in the full complaint list.
Interior & seats
Reports naming seats, latches, locks, linkages and interior fittings.
From owner reports, verbatim
The vehicle is experiencing severe frame flex causing the 2 passenger side entry doors to open while traveling down the highway in addition to rubbing the interior cabinetry against the side walls of the interior and causing the furnishings to be damaged. When the doors are wide open items can easily fly out of the vehicle while traveling making my personal items projectile hazards. The vehicle has been diagnosed for frame issues by an authorized repair facility "Busted Knuckle RV" in Las Vegas Nevada. Grand Designs did not authorize the repair facility to perform the necessary inspection work and Informed the shop that I would be liable for the cost of the initial tear down inspection that can average $5,000.00 The unit has had saw dust and rub marks on the interior since we first purchased the unit and transported it from Texas to our home in Arizona. We were not sure what caused this rubbing of the furniture on the interior and were later informed that this is caused by extreme frame flex or failure. The pinch style moldings that cover the seams on the front cap of the rv have loosened while driving and flap in the wind while traveling down the highway, I have since been forced to apply silicone to keep these in place. This style of molding is designed to stay in place without having to apply any adhesive to them. The doors have opened while on the highway on several occasions causing great concern considering we only use the vehicle approximately 6 trips per year.
Roof Membrane separating from nose cap, nose cap separating from roof membrane. 5th wheel pin box sinking up into rv upper deck when lowering onto the truck. Cargo and main doors open during transport. Sawdust on dresser in nose of the RV. Lag Screws unscrewing and/or loose in the upper deck. Stress fractures in fiberglass on the cap of RV. Pinch molding coming loose from underside of 5th Wheel skin. Screws backing out and/or breaking underneath the upper deck nose cap. Insulation underneath the front of the RV is falling off. Back Patio bubbling. Rear axle leaf springs bolt and bushings coming out during transport. Screws on top of the upper deck by rain gutters keep coming loose.
Too few reports in this category for a page of its own — they appear in the full complaint list.
Electrical
Reports naming the electrical system — wiring, battery, charging, control modules, infotainment and electrical accessories.
From owner reports, verbatim
The contact owns a 2020 Grand Design Momentum RV. The contact stated that while the RV was parked, the contact heard an abnormally loud popping sound coming from behind the sleeping cabinets at the camping ground. The contact performed an inspection and noticed that the 110-volt electrical wires in the RV had shifted during travel and were touching the subframe of the RV. The contact noticed smoke coming from underneath the RV, and the refrigerator circuit braker then tripped. No warning lights were illuminated. The RV was taken to the dealer, where it was diagnosed with a failed electrical wiring system and junction box. The contact was informed that the wiring system and the junction box needed to be replaced, and the wires needed to be re-routed. The contact was informed that the repair was not covered under warranty. The manufacturer was made aware of the failure, and a case was filed. The failure mileage was approximately 12,000.
Too few reports in this category for a page of its own — they appear in the full complaint list.
Other / unspecified
Reports whose component NHTSA recorded as unknown, or that do not map to one of the categories above.
From owner reports, verbatim
The contact owns a 2020 Grand Design Momentum RV. The contact stated that while the RV was parked, the contact heard an abnormally loud popping sound coming from behind the sleeping cabinets at the camping ground. The contact performed an inspection and noticed that the 110-volt electrical wires in the RV had shifted during travel and were touching the subframe of the RV. The contact noticed smoke coming from underneath the RV, and the refrigerator circuit braker then tripped. No warning lights were illuminated. The RV was taken to the dealer, where it was diagnosed with a failed electrical wiring system and junction box. The contact was informed that the wiring system and the junction box needed to be replaced, and the wires needed to be re-routed. The contact was informed that the repair was not covered under warranty. The manufacturer was made aware of the failure, and a case was filed. The failure mileage was approximately 12,000.
Too few reports in this category for a page of its own — they appear in the full complaint list.
Brakes
Reports naming service brakes, the antilock braking system, brake hoses, master cylinders or the parking brake.
From owner reports, verbatim
Issues with: - original drum breaks failed due to incorrect wiring, requiring 100% assembly replacement. - front wall separation - trim and cabinets moving and separating from walls - missing and broken lag bolts - front weather stripping separated from front cap - excessive sawdust under cabinets after any travel - wallpaper wear showing excessive movement of front bed overhead cabinets during travel - floor joists separating from upper floor - slides opening during travel - leaf spring hangers bending and twisting, and breaking off - spare tire mount failed during highway travel, and spare tire fell off on highway - contacted manufacturer to report in 2024 and they indicated we should self-replace the missing and damaged lag bolts with larger 1/2 inch ones. This was done, and they continue to back out on every trip whether 5 miles or 500 miles.
Too few reports in this category for a page of its own — they appear in the full complaint list.
Tires & wheels
Reports naming tires, wheels, hubs, or the tire-pressure monitoring system.
From owner reports, verbatim
Issues with: - original drum breaks failed due to incorrect wiring, requiring 100% assembly replacement. - front wall separation - trim and cabinets moving and separating from walls - missing and broken lag bolts - front weather stripping separated from front cap - excessive sawdust under cabinets after any travel - wallpaper wear showing excessive movement of front bed overhead cabinets during travel - floor joists separating from upper floor - slides opening during travel - leaf spring hangers bending and twisting, and breaking off - spare tire mount failed during highway travel, and spare tire fell off on highway - contacted manufacturer to report in 2024 and they indicated we should self-replace the missing and damaged lag bolts with larger 1/2 inch ones. This was done, and they continue to back out on every trip whether 5 miles or 500 miles.
Too few reports in this category for a page of its own — they appear in the full complaint list.
Higher-selling and older vehicles accumulate more reports. Counts are not failure rates and are not directly comparable between vehicles that sold in very different numbers.
Elsewhere on this vehicle
Data sources
- NHTSA Office of Defects Investigation — owner-reported complaints and the components recorded on them
Data on this page last refreshed .