Can 2019 Grand Design Momentum 381M be Upgraded to 8K Suspension Parts in Stages

Updated 12/15/2025 | Published 11/22/2024

Products Featured in This Question

Roadmaster Comfort Ride Leaf Spring Suspension Kit w/ Shocks - Triple 8K, 3" Trailer Axles

(146)

$3873.33

DeeMaxx Disc Brakes - 13" Hub/Rotor - 8 on 6-1/2 - Maxx Coating - Grease - 8,000 lbs

(1)

$733.49

Question:

I have a 2019 Grand Design Momentum 381M - triple 7k axel railer and I am interested in the Road Master Slipper Spring with shocks suspension system. What rating of suspension kit should I consider installing 7K or 8K? Current trailer weight 19740 lbs / pin weight 3140 lbs / axel weight 16600 lbs. I am also interested in converting to disc brakes and axel increase to 8K. I was wondering if it can be installed in stages? If I need to upgrade to 8K axels, can I install 8K axels and the 8K Roadmaster Slipper Spring with shocks slipper springs suspension system and use my 7K drum/hub brake assembly that is currently on the trailer until I can save some money to purchase the 8K disk brake system for the trailer. Do the 8K axels have the same bolt pattern at the spindle as the 7K axle so I can install my current 7K drum/hub assembly on the 8K axle?

asked by: Kyle S

Expert Reply:

Hey Kyle, good to hear from you again!

You can definitely upgrade the suspension components on your 2019 Grand Design Momentum 381M in increments because the 7K and 8K brakes match enough that it can work out that way, you just need to make sure the bearings for your current brakes will match up with the 8K axles when you purchase them.

We unfortunately don't carry any axles rated higher than 7K so you'll have to take the bearings numbers you currently have with you to your local RV dealership or trailer shop so they can make sure you get the right thing, but the Roadmaster Comfort Ride Leaf Spring Suspension Kit w/ Shocks # RM-2460-2580-3 we have will be compatible so you can get started with that.

When it comes to swapping your brakes over, I recommend picking up the DeeMaxx Disc Brakes # DE63AR because the Maxx coating is rated for over 1,000 hours of salt spray which is had and shoulders above what the rest of the industry stands behind, so you can have confidence in the life of this product.

expert reply by: Jon G

Jameson C.

12/15/2025

Hey Kyle, how did things go with upgrading the suspension on your Grand Design Momentum? Were you able to match your current bearings with the 8K axles and start using the Roadmaster Comfort Ride kit? Your update could make it easier for others planning a similar staged upgrade.