How To Determine If Boat Trailer has 10 Inch or 12 Inch Brake Assemblies

Question

Question:

I have a boat trailer and need to replace the brakes. I know I have a #84 spindle, 15 inch rims 5 lug at 4.5 inch spacing...Is there a way to tell if I need 10 inch or 12 inch brakes? Thanks.

asked by: Paul

0

Expert Reply:

When determining if you need 10 inch or 12 inch brake assemblies there are a couple of easy things to check to confirm the fit for your trailer. The first thing is you can measure the diameter of your hub. The second thing is you can look at the brake flange, if it has 4 bolts then it is 10 inch if it has 5 then it is 12 inch.

Because you know you have a #84 spindle we can be confident that you have a 3,500 lb axle and you will need the 10 inch assemblies. I recommend the Hydraulic Brake Kit - Uni-Servo - Free Backing # AKFBBRK-35-D which will fit your current hubs. If you also want to upgrade your hubs while you are at it, I recommend the Galvanized Hub/Drum # AKHD-545-35-G-K for your boat trailer. If you have EZ Lube Spindles then # AKHD-545-35-G-EZ-K will come with the grease cap that allows for that zerk access.

If you have electric brakes on your boat trailer then you can use # AKEBRK-7-SA for 12 inch or # AKEBRK-35-SA for 10 inch assemblies.

expert reply by: Jason S

0

Randell

12/1/2024

I have a two axle trailer custom built for a cobalt 226 with disc brakes on the front axle only. In 2018 I had a shop replace the brakes. We used the boat very little and only made short moves from storage to the ramp. We made a trip to San Antonio from San Francisco when we moved in May 2022. Upon arrival the pads were almost completely worn away. We replaced the pads and have put less than 500 miles on the trailer. While doing maintenance repacking the bearings we found that the right side pads were already heavily worn unevenly. We decided the mounting brackets may have bent so we replaced the mounts. Calipers and pads with new. They are tie down G5 9.6 disc brakes. After a short trip to the storage yard of less than 10 miles the brakes are locking up. Question Should this trailer have larger brakes? Brakes on both axles? Or have we done something drastically wrong? Thanks

Robin H.

12/1/2024

@Randell assuming you have 3,500 lb axles it is probably safe to assume your brakes match the capacity of the axle so you're putting a lot on a single set of brakes. I would definitely add brakes to that other axle. As an example, say you do have two 3,500 lb axles and your Cobalt 226 is 5,000-6,000 lbs loaded on the trailer. Your single set of brakes designed for 3,500 lbs is going to wear down significantly faster because it has to stop all of that extra weight beyond its capacity. If you share that weight between two sets of brakes, just like you do with the axles, the wear on the brake pads will be normal since the combined rating is 7,000 lbs which is in line with your boat and trailer.

Randell

12/1/2024

@RobinH Thanks for your quick reply. Sort of disappointed with cobalt’s choice af brakes on the trailer.

Robin H.

12/1/2024

@Randell if you can identify the axles I can help you find replacement brakes and an extra set of brakes for the axle without them. Tie-down engineering is no longer around so we wouldn't be able to match the other set but we have good replacement options. While you're at, it you will also need to make sure that other axle has a brake flange. If it doesn't, you'll have to add one or replace the axle with one that has a brake flange to install another set of brakes. I'm sure wherever/whenever that trailer was built it only needed brakes on a single axle by law so that is what they did to save money. Just like a lot of utility trailers for heavier loads can come without brakes because the state they're manufactured in doesn't require them by law, even though they really should come with them.

Answer 1

Hey Roger, thanks for getting in touch. I can certainly point you in the right direction here, but there is no way to know exactly what hub you need based on the trailer model or VIN. Trailer manufacturers just do not make this kind of information…

view full answer...

Answer 2

Hello Casey, thanks for reaching out. It sounds like the 2,200 lb Timbren Axle-Less Trailer Suspension #ASR1THDS03 will be sufficient for your build. Even if the GVWR is 1,500 lbs and your water tank is full, you would still be safely under 2,200…

view full answer...

Answer 3

The Trailer Hub and Drum Assembly part #AKHD-545-35-EZ-K would be an excellent replacement for a Tru-Ryde Hub/Drum RVD-H-545. Then for new brakes, I recommend the Hydraulic Trailer Brake Kit part #AKFBBRK-35.

view full answer...

Answer 4

For your application you need the Easy Grease Trailer Hub and Drum Assembly for 3.5K Axles #AKHD-545-35-EZ-K to replace the Tru-Ryde RVD-H-545 trailer hub/drum assembly. This is designed for the industry standard #84 spindle so it uses inner bearing…

view full answer...

Answer 5

The Grease Seal #168233 is the correct seal to replace the AD2527. Your seal is an older design that wasn't the greatest hence the reason you don't see it around anymore. The new seal is a double lip seal that make it right for your boat…

view full answer...

Answer 6

Alejandro, in order to find out what size brakes your boat trailer needs you can either pop off your hub and measure the width and depth of the drum, or, you can let me know what size axle you have and we'd be able to find out what size brakes…

view full answer...

Answer 7

To determine the size of the brake assemblies you need you have to measure the depth and width of the hub drum on the axle like what you see in the picture I attached. The most common size is 2-1/4 inch wide like the #T4071600-500 that you…

view full answer...

Answer 8

It could be a tow package fuse on the vehicle. Use the owners manual to find the locations of fuses/relays related to the tow package wiring to check them and replace as needed. If the issue is not a fuse or relay then you can test the vehicle side…

view full answer...

Answer 9

Surge brakes use a hydraulic actuator to push fluid to the cylinder piston to activate the brake shoes on drum brakes or brake pads on disc brakes. This pressure should only be applied when weight is pushing against the hitch ball, so no pressure…

view full answer...

Answer 10

The left side is the driver side, right side is passenger side. On a trailer brake assembly like #23-105 the arm that the magnet is on points to the front of the trailer and the magnet always will be on the bottom. I have included a picture that…

view full answer...

Answer 11

There is no specific torque rating for the castle nut that holds your hub in place. We recommend tightening the castle nut down until it stops, and then backing it off to the next notch wheel the tang washer will fit into the castle nut. Over…

view full answer...

Answer 12

We don't have any way of knowing the brakes you need for your Shorelander boat trailer but can tell you how to determine the right ones. To determine the brake assemblies that will fit your trailer, you need to know your axle's weight…

view full answer...

How To Determine If Boat Trailer has 10 Inch or 12 Inch Brake Assemblies

Products Featured in This Question

Product Page this Question was Asked From

Featured Help Information

Miscellaneous Media

Continue Researching