Disc Brakes Recommendation For 3500 Lb Boat Trailer

Question:

I want to add disc brakes to existing shorelander boat trailer 3500 lb axle. trailer+boat 2500 lbs.. Axile has 4 hole flange mounted..so appears I could use Kodiak slip on discs to existing hubs ?: It mentions 1/2 inch hub to hub increase..so that means disk pushes each wheel out 1/4 inch ?? In that case studs should be long enough still...but if 1/2 inch on each wheel , may need to put in longer studs?? Also, will caliper mounting plate slip over axle etc w/o removing wheel g=hub or does hub/bearings have to be removed to get mounting plate on ? Thanks//

asked by: Fred B

Helpful Expert Reply:

The Kodiak disc brake kit you asked about, part # K2R35DS, will fit 3500 pound axles with wheel sizes 14 inches or larger. The 10 inch rotors have a 5 on 4-1/2 bolt pattern. The additional 1/2 inch would mean the wheels would indeed be mounted approximately 1/4 inch further out on each axle. The existing hubs along with the bearings and races would have to be removed.

You mentioned that the axle has a 4 bolt flange already welded to it. I have attached a photo of how the brake mounting flange is attached to an axle, and I have also attached a photo that shows the dimensions of a brake mounting flange that is typical for a 3500 lb axle. The attached photos are of part # 4-35.

There are a few other things to consider when adding disc brakes to your trailer. When changing to a disc brake system on a trailer, not only do the brakes themselves need to be considered, but you need to select a brake actuator that is designed specifically for disc brakes. Hydraulic disc brakes operate at a higher pressure (1,500 psi) than drum brakes (1,000 psi). A drum brake actuator will not work with disc brakes. I suggest a kit that will give you all of the parts needed to add disc brakes to your trailer. There is also a considerable cost savings when using a complete kit.

I recommend the Titan Disc Brake Kit and Actuator, part # T4843300. This will give you the complete kit needed to switch over to disc brakes on your trailer. In the kit you will find the hub and rotor assemblies along with the grease seals, bearings, races, and bearing protectors. You also get the calipers with mounting brackets and hardware, as well as a brake actuator with electric reverse lockout that lets you back up without actuating the trailer brakes. The swing away coupler fits 2 inch trailer balls and includes a breakaway kit. This kit is for wheel sizes from 13 to 15 inch and the bolt pattern is 5 on 4-1/2. The stud length will be no issue as they are already included on the new hubs.

I have attached links to some articles that may help.

expert reply by: Jeffrey L