Disc Brake Conversion Kit For 2021 Grand Design Solitude 310GKR With 7,000 lb Axles

Updated 01/30/2025 | Published 10/30/2024

Products Featured in This Question

Hydrastar Disc Brake Kit w/ Actuator for Tandem Axle Trailers - 13" Hub/Rotor - 8 on 6-1/2 - 7K

(56)

$2023.50

Tekonsha Prodigy P3 Trailer Brake Controller - 1 to 4 Axles - Proportional

(6457)

$170.94

DeeMaxx Disc Brake Kit - 13" Hub/Rotor - 8 on 6-1/2 - Maxx Coating - 9/16" Bolts - 7K

(8)

$879.90

Hydrastar Electric Over Hydraulic Actuator Kit for Disc Brakes - 1,600 psi

(217)

$1189.54

Question:

Hi, I am looking to upgrade the electric drum brakes on my 2021 Grand Design Solitude 310GKR to disc brakes. Could you please guide me to which kit is compatible? The trailer has 7000 axles, 17.5 wheels, 8 lugs, 9/16 studs, leaf suspension with Moryde CRE3000. Thank you,

asked by: Rick B

Expert Reply:

Hello Rick, thanks for reaching out. The 7,000 lb axle on your 2021 Grand Design Solitude 310GKR uses a standard bearing combination, so finding compatible disc brakes will be easy. Here is what I recommend:

- DeeMaxx Disc Brake Kit - 13" Hub/Rotor - 8 on 6-1/2 - Maxx Coating - 9/16" Bolts - 7K # DE68YR

- Hydrastar Electric Over Hydraulic Actuator Kit for Disc Brakes - 1,600 psi # HBA16-252-82

The disc brake kits are enough for one axle, so you will need two kits if you want brakes on both axles. I recommend this DeeMaxx kit specifically because it has the 9/16" studs which you will want to stick with.

The Hydrastar kit is a full conversion kit so you get everything you need to convert from electric drum to EOH disc brakes. Overall disc brakes are more durable and provide more stopping power than drum brakes.

You will also want to make sure the brake controller if your cab is compatible with EOH brakes. Pretty much any aftermarket controller will be OEH compatible or will have an EOH mode you can switch to. A lot of factory brake controllers can have compatibility issues with EOH brakes so if you have a factory controller I recommend switching to something like the Tekonsha P3 # 90195.

We wrote a guide that goes over the process of adding EOH brakes to a trailer, and you will find it linked below. Feel free to reach out if you have any other questions.

expert reply by: Jesse M

Rick B.

11/7/2024

Thanks Jesse. I've been researching this and am leaning towards the Brakerite actuator DX82KR (because it's now compatible with my '21 Chevy. 2500 controller according to some sources), and the Kodiak disc brakes (KOD33FR). Thoughts on this pairing? Also, can I run grease with these disc brakes or does it need to be oil. Also, I'm planning on getting a couple X-Factor cross braces. Which mounting brackets should I put these on (e.g. front, center, rear).?

Jesse M.

11/11/2024

@RickB The BrakeRite # DX82KR is a good choice if it works with your truck. No reason for me to talk you out of it. The Kodiak # KOD33FR will work for your 7K axles but it comes with oil seals and caps so if you go with this kit I do recommend sticking with the oil bath instead of grease. If you want to run with grease get # KOD53FR instead. As far as the crossmember, part # MR33WR is what you will need. You can do just one on the center hanger if you wish. It is recommended to do a total of 3 crossmembers for optimal support.

Justin T.

1/29/2025

Hi, I saw this post and had a question. I have a 2022 GD Solitude with Dexter 7k's. I pulled a hub to match the bearings. I also used a digital caliper to measure the studs. My OEM drums measure .52in. So, I purchased the complete hydrastar kit HSE7K-T1. I just received it and opened the box. I just wanted to make sure everything was there, and the piece matched. I'm glad I did as I noticed my lug nuts are bigger than the studs on the hydrastar disc. The studs on the discs measure .47in. What am I missing? ET customer service was a help but could really only offer to return the items because they believe I received a defective batch. I'd like to do this upgrade but want to make sure I'm not the problem. Am I measuring wrong, any help you could provide would be greatly appreciated. Thanks!

Jesse M.

1/30/2025

@JustinT The # HSE7K-T1 kit you mentioned comes with 1/2" studs. It is hard to imagine that you received a defective kit that just so happened to have the wrong size studs on every hub. Most 7K axles use either 1/2" or 9/16" studs. So I wonder if your old setup used 9/16". That would explain the discrepancy. It could also have to do with what part of the stud/threads you are measuring from. At this point you can either get your hands on some 1/2" lug nuts like part # AM90049. Or we would have to start a return so you can order a different kit with 9/16" studs.

Justin T.

1/30/2025

@JesseM Thanks Jesse. That is what I thought. There seems to be too much play between the rim holes and the new studs. So, I don't feel comfortable just using different studs. I've already started the return process, ET is always awesome. I just wasn't sure what I was doing wrong. I'm guessing my OEM must be 9/16 so I'll have to see what those kits look like. Thanks for the information!

Jesse M.

1/30/2025

@JustinT Glad we are on the same page. 9/16" studs are what we generally recommend for axles 7K and up so sticking with that is a good call. Feel free to come back anytime you need anything.