Recommended Disc Brake Conversion Kit for 2020 Grand Design Momentum with Triple Axle

Updated 02/03/2020 | Published 02/01/2020

Products Featured in This Question

Dexter Disc Brake Kit - 12-1/4" Hub/Rotor - Oil - 8 on 6-1/2 - E-Coat - 7,000 lbs

(3)

$2233.02

Replacement Trailer Hub Bearing - 14125A

(146)

$16.54

Replacement Race for 14125A Bearing

(1305)

$4.84

Replacement Race for 25580 Bearing

(1305)

$13.28

Replacement Trailer Hub Bearing - 25580

(2192)

$24.30

Hydraulic Line Kit, 3rd Axle - Drum and Disc

(6)

$96.33

Hydrastar Electric-Hydraulic Actuator w/ Line Kit for Disc Brakes - 1,600 psi

(27)

$1310.38

Grease Seals 10-36 (pair)

(2636)

$10.09

Kodiak Synthetic Bearing Oil for Oil Bath Hubs - 8 oz Bottle

(46)

$30.64

Question:

Hello, I have a 2020 39.7 triple axle Grand Design Momentum that I want to convert to the disk brakes/oil bath as in the video. My trailer has dexter 7000 lb axles with 8 on 6 1/2 with 1/2 wheel studs, 16inch tires. I see the K2HR79 shows 9/16 wheel studs can you get 1/2 wheel studs instead of the 9/16? Axle tag photo attached for reference. Thank you

asked by: Mike S

Expert Reply:

I have a solution for you, but unfortunately the # K2HR79 cannot accept 1/2" wheel studs. In order to convert from electric brakes to disc brakes with an oil bath, that will also allow you to use your current 8 on 6-1/2 bolt pattern with 1/2" studs you'll want to use the Dexter Disc Brake Kit # K71-694-695-11. These rotors have an E-coat finish for better protection against the elements and the hub comes with the bearings, races, seals and oil caps included, so you won't have to track down a variety of parts to complete this conversion. This kit is designed for use on 7k axles and with wheels between 16" and 17" diameter.

The Dexter Disc Brake Kit uses the following bearings, so you'll want to verify that you have a #42 spindle that takes the following bearing sizes:

Bearings (included)
Inner bearing: # 25580
Outer bearing: # 14125A
Races (included)
Inner race: # 25520
Outer race: # 14276
Seal: # 10-13 (included)
Inner diameter: 2.250"
Outer diameter: 3.376"

Once you've verified the bearings that your current hubs have match the new disc brake kit, there are some other parts you'll need this complete part list to get a working system on your triple axle Grand Design Momentum.

Disc Brakes: part # K71-694-695-11 (1 set per axle)
Brake Actuator and Lines: part # CAR-HBA16-2 (enough lines for tandem axle) plus # 9579-01 (to add lines for 3rd axle)
Oil: Kodiak Synthetic Oil Lube # XLPROLUBE (1 per axle)

If you determine that your spindles have different bearings (check the numbers stamped on the back of them), please let me know what you find and I can recommend an alternative solution. I've also linked some review videos on these products in case you'd like to check those out as well.