Advice on Replacing Old Surge Brake Coupler with Non Surge Straight Box Coupler Shaft

Published 08/30/2016

Question:

I have a trailmaster 26ft duel axle boat trailer with an old surge coupler that I need to replace with just a coupler since the trailer brakes will be electric so the hydraulic pump is no longer needed. The box shaft dimensions are 3inch x 4-5/8inch deep and is held in with a pin top and bottom through the frame. The ball is 2-5/16 I have attached a picture. I dont see anything on your site that has a top pin hole. The boat is a 1993 chaparral signature 24 if that helps.

asked by: Leigh G

Expert Reply:

Thank you for including images, this was a great help to me understanding what you will need to do to equip your trailer with electric brakes.

The best thing for you to do is to immobilize the surge coupler. To do this you can weld the inner part of the surge coupler to the outer sleeve, as seen in the attached photo in blue. You can also drill a 5/8 inch hole through the unit and insert a grade 5 or 8 bolt through it. If you do this you will want to make sure you choose a spot that has both the inner and outer portions of the coupler, seen in green. If you remove the coupler, you will have to rebuild the frame due to the frame not being designed for a standard replacement. I have outlined the frame in pink for you to better see.

Once the coupler is immobilized it will serve your trailer as a standard coupler, which will be great for the electric brake upgrade.

It will be up to you to decide which route you would like to take but you will not find a part that you are describing because it doesn't exist.

expert reply by: Jackie C