Contact Sales

New 2026 Grand Design Momentum 399M

Toy Hauler Fifth Wheel

Stock #70900

Ripon

Ultimate Toy Hauler Luxury

1 of 24

+24

MSRP: $200,978

45ft long
19,170 lbs
Sleeps 4

3 slides
Kitchen Island

Two Entry/Exit Doors

See All Specs

Specifications

Sleeps	4	Slides	3
Length	44 ft 10 in	Ext Width	8 ft 5 in
Ext Height	13 ft 6 in	Int Height	8 ft 5 in
Interior Color	ARTISAN	Hitch Weight	3406 lbs
GVWR	23500 lbs	Dry Weight	19170 lbs
Fresh Water Capacity	140 gals	Grey Water Capacity	104 gals
Black Water Capacity	52 gals	Tire Size	17.5"
Furnace BTU	35000 btu	Fuel Capacity	60 gals
Available Beds	Queen	Refrigerator Type	12V Stainless Steel
Refrigerator Size	20 cu ft	Cooktop Burners	3
Number of Awnings	3	Axle Weight	7000 lbs
Garage Size	12 ft 6 in	LP Tank Capacity	30 lbs
Water Heater Type	On Demand	AC BTU	30000 btu
TV Info	LR 50" LED TV, Garage 32" LED TV, Patio 65" TV	Awning Info	9', 12', 14' Power w/LED Lights
Axle Count	3	Washer/Dryer Available	Yes
Number of LP Tanks	2	Shower Type	Shower w/Seat
Electrical Service	50 amp	VIN	573FM4731TBB04796

Description

Grand Design Momentum fifth wheel toy hauler 399M highlights:

Front Private Bedroom
Kitchen Island
Hybrid Desk/Dinette
Unobstructed Pass-Thru Storage
Side Patio

This toy hauler has all the comfort and convenience you could ask for! Once you have unloaded your toys from the 12' 6" separate garage, you can start lunch on the exterior griddle located by the side patio. There is also a 65" TV here and a 1.7 cu. ft. refrigerator to entertain guests! And if you have guests staying over, you can choose to add the optional Liftsuite system with underside can lights in the garage. If the weather isn't cooperating, you can make meals in the fully equipped interior kitchen, complete with an island, pantry, pull-out countertop extension and more. An L-shaped sofa with recliners is in perfect view of the 50" TV and fireplace, and there is even a hybrid desk/dinette with windows where you can get some work done if needed. Head towards the front to freshen up in the full bath before heading to bed in the private bedroom. Here, you'll find a queen bed slide out with an optional king bed, a large closet with washer and dryer prep, plus a dresser with TV prep if you want the option to watch movies in bed!

The Momentum fifth wheel toy haulers by Grand Design are built for four seasons of travel with your off-road toys and include luxurious accommodations throughout for extreme living! Each is constructed to a superior standard with the fully enclosed and heated underbelly and storage area, the 5-sided aluminum cage, and the triple insulated garage floor. The MORryde CRE3000 suspension system and rubber pin box, plus the upgraded axle hangers provide the performance and smooth towing you desire, while the interior offers luxury such as color changing LED accent lighting, hardwood cabinet doors with hidden hinges, and a central vacuum system. Each toy hauler also includes four packages, including the Garage Package with Tuff-Ply gas and oil-resistant flooring, the Weather-Tek Package with a Stealth AC System, and the Interior Luxury Package with solid surface countertops!

Options:

20 CU FT 12V REFRIGERATOR
3RD A/C
3RD A/C PREP
6K WATT GENERATOR
AUXILIARY FRESH WATER TANK
BEDROOM A/C
EXTERIOR PKG
GARAGE LED HD TV
GARAGE PKG
GARAGE SUITE
GEN III 3 SEASON DOOR
HEAT PUMP A/C
KING BED UPGRADE
KITCHEN POWER FAN
LUXURY INTERIOR PKG
MORRYDE 7K INDEPENDENT SUSPENSION
OMNICONNECT
PATIO CHAIRS
REAR ALUMINIUM DECK SYS
ROCKFORD FOSGATE STAGE 1
RVIA SEAL
SAFERIDE
SOLAR½ PKG
UNDER UNIT LED LIGHT KIT
UPGRADED H-RATED TIRES
WEATHER-TEK INSULATION PKG

Call Today 209-924-4022

Features

Standard Features (2026)

Exterior

Keyed Alike™ Ramp Door Latches
2nd Patio Awning w/ LED Lights
3rd Awning w/ LED Lights
Exterior Color Changing LED Accent Lighting
High-Gloss Gel Coat Exterior Sidewalls
Door Side Exterior Spray Port
Frameless Tinted Windows
Walk-On Roof
17.5" Spare Tire (Undermount)
MORryde Strut Assist Entry Step
Slam-Latch Baggage Doors
Mo Secure
Gen III 3 Seasons Doors (Opt)

Construction

101" Wide Body Construction
5-Side Aluminum Cage Construction
Fully Enclosed and Heated, Underbelly and Storage Area

Running Gear

Upgraded Axle Hangers
Heavy Duty H-Rated Tires
Heavy Duty 7,000 lb. Axles with ABS Brakes
17.5" H-Rated Aluminum Wheels
MORryde® Independent Suspension 2.0

Frame & Chassis

6-Point Hydraulic Leveling System
MORryde® Pin Box
101" Wide Body Super Chassis w/Drop-Frame Storage

Interior

Interior Color Changing LED Accent Lighting
Hardwood Cabinet Doors w/Hidden Hinges
Recliner Sofa w/Adjustable Headrest or Flip Down Cupholders
Central Vacuum System w/ Tools and Dust Pan
Plywood Drawer Bottoms

Kitchen

Microwave
Professional Grade Stainless Steel Cooktop
12-Volt High Power MaxxAir w/Rain Sensor
Window Behind Range
Kitchen Barstools w/ Extended Countertops
Smart Sink w/Removable Cutting Board, Produce Strainer and Glass Rinser

Electrical

Solar Prep (10-gauge wiring with universal MC4 connectors)
75 Amp Converter
12V Battery Disconnect

HVAC

12V High Power Fan (Kitchen)
35k BTU High-Capacity Furnace
Fireplace w/ 5,000 BTU Electric Heater
StealthAC Smart AC System
Attic Vent
High-Capacity Heat Ducts

Plumbing

Exterior Spray Port (Door Side)
12V Tank Heaters
Sewer Hose Storage Area
Whole House Water Filtration System
All-In-One Enclosed and Heated Utility Center

Bedroom

Under Bed Storage Area
Individually Switched Reading Lights Over Bed
Bedside 110-Volt & USB Outlets
Window Above Master Bed Headboard
60" X 80" Queen Bed Pillow Top Bed Mattress

Bathroom

Skylight Above Shower
Porcelain Toilet
Medicine Cabinet w/Mirrored Door (N/A 410TH)
Undermount Lav Sink
One-Piece Fiberglass Shower w/Glass Door & Teak Bench Seat

Appliance

Fireplace with Electric Heater
Stainless Steel 20 Cu. Ft. Refrigerator
30" Over-The-Range Microwave

Electronics

OneControl™ System
Back-Up Camera Prep
Exterior Cable/SAT Plug-In
LED Smart TV in Living Area
LED TV in Bedroom
Rockford Fosgate Stereo Entertainment System w/HDMI and App Controls
Exterior Speakers
No-Crank Digital TV Antenna w/Booster
LED TV in Garage
OmniConnect On-Board WiFi Ready

Packages

Exterior Package

Satellite TV Prep
MORryde Strut Assist Entry Step
Aluminum Quad Entry Steps - Garage Entry
7,000 lb. Axles w/Self Adjusting Brakes, Wet Bolts and Bronze Bushings
17” Aluminum Wheels (120PSI Rated)
Cooper Tires® 17.5" All-Steel H-Rated Tires
Slam-Latch Baggage Doors
Frameless Tinted Windows
Exterior Security Lights
Power Patio Awning w/LED Lighting
Folding Roof Ladder
White Gel Coat Fiberglass Front Cap
12V Battery Disconnect
All-In-One Exterior Utility Center
50 Amp Service
Converter
Enclosed Fuel Station w/ Dual Fuel Tank
Partial Paint Gel Coat Fiberglass Front Cap

Luxury Interior Package

49" Class LED TV in Living Area
Stereo Entertainment System w/Bluetooth and App Based Controls in Living Area
Washer/Dryer Prep
On Demand Water Heater
Roller Shade Window Coverings (Main Living Area and Bedroom)
Recessed LED Puck Lighting
Solid Surface Countertops w/ Sink Covers
Stainless Steel Undermount Kitchen Sink
Chef Inspired Range & Oven w/ Cover
Kitchen Pantry w/ LED Light Strip
Garage Control Panel

Garage package

32" Class LED TV in Garage
Protective Diamond Plate on Garage Sidewalls
2,500 lb Rated Flush-Mount Tie-Downs
Ram-Air Garage Vents on Both Sides
Tuff-Ply Gas and Oil Resistant Garage Flooring
FastRamp™ Rear Ramp Door
Triple Insulated Garage Floor

Weather-Tek Package

R-Value Equivalent (R-40 Roof / R-45 Floor / R-11 Sidewalls / R-40 Garage Floor / R-24 Slide room Floor)
Fully Enclosed and Heated, Underbelly and Storage Area
Enclosed and Heated Low Point Drains
Engineered Underbelly Airflow Heat Paths
Stealth AC System w/ Insulated A/C Ducts
Attic Vent
Plumbing Line Insulation Barrier

See us for a complete list of features and available options!

All standard features and specifications are subject to change.

All warranty info is typically reserved for new units and is subject to specific terms and conditions. See us for more details.

Due to the current environment, our features and options are subject to change due to material availability.

Favorite RVs

Save your favorite RVs as you browse. Begin with this one!

Excellent experience
"Buying a travel trailer from Happy Daze has been one of my smoothest, hassle free transactions for an RV to date. My sales rep Dan Risk was an excellent communicator and did his best to answer all my questions. He really came across as an advocate for me the customer and really got me locked into buying ... More »

Aaron
Thanks alot!
"My son, wife, and I went to the RV show in CalExpo on April 10, 2010 to just looked at the RV's and didn't have plan to buy that time but with the help of Peter Stromberg, we saw this 2010 Trail Sport 20RD and right away we liked it. We went home and talked about it and right away we called Peter and ... More »

Steven
Thank You
"We just picked up our new Allegro Open Road and are so pleased. You guys took care of us so well. Happy Daze RV must have the best customer service in California. Thanks to Dan, Ronnie, Tory and everyone else who helped us make this happen. The kids love that they have their own bunks now! I will be ... More »

Bradley

We are here to help, call us at
209-924-4022 or Contact Us

We are here to help!

209-924-4022
Contact Us
Contact Sales

Happy Daze RV is not responsible for any misprints, typos, or errors found in our website pages. Any price listed excludes sales taxes, registration, tags and delivery fees. Manufacture pictures, specifications, and features may be used in place of actual units on our lot. To preserve the quality and mileage of our coaches, we only do test drives with a qualified offer to purchase.

New 2026 Grand Design Momentum 399M

399M Floorplan

Specifications

Description

Features

Connect with us!