Boat Trailer Overhaul

It's about that season again...

by “Capt’n Pauley” Paul Esterle

I had a chance to inspect Ternabout’s trailer after I had the yard put her on jackstands for the bottom painting. What I saw was worse than I anticipated. I hadn’t done any maintenance on the trailer, except for new tires and packing the wheel bearings, for over ten years and it showed.

The springs were rusty and sagging, the insulation on the wiring was cracked, the bunks needed help and the coupler and chains were rusty and suspect as far as strength went. The aluminum frame was in good shape and needed no welding; that was good news. With the boat off the trailer, it was an ideal time to upgrade.

Spring Replacement
This was the big one. The original springs were sagging and tired. Looking at the original trailer documents, I don’t think they were ever of a high enough load rating for the boat loaded and ready to sail. In addition, the shackles and bushings were also questionable.

Luckily, I have a boating store nearby that has an impressive inventory of trailer parts and accessories. I was to make frequent visits there during the upgrade.

My springs had an eye at each end; other trailers have different spring configurations. With the eye-to-eye spring measurement, I was able to find an exact size replacement with a higher load rating than the original spring. I also purchased new spring pads, axle U-bolts, shackle and shackle bolt kits as well as new shackle bushings.

After I jacked up the trailer and supported the frame, the fun commenced. At some point in her life, Ternabout and her trailer had been in salt water. That and the years of age ensured that all the nuts and bolts were corroded beyond easy removal. I finally resorted to cutting the bolts and nuts off with a fiberglass reinforced cut off disc in my Dremel (don’t use the un-reinforced discs, they shatter!).

The next problem was bolting the shackles and springs together. The shackles are heavy steel plates that connect the spring eye to the frame, one on either side. A large bolt goes through the shackles and the bushing in the spring eye. The problem was that the top portion of the shackle bolt had ridges that were meant to force their way into the shackle hole, keeping the bolt from rotating.

I’m sure a trailer manufacturer could put these bolts in place quickly with an impact wrench, but I didn’t have one. I ended up buying a heavy-duty socket and an eighteen-inch breaker bar. That, in combination with a length of pipe over the breaker bar handle, finally gave me enough leverage to seat the bolts.

The rest of the spring installation went quickly. The new spring pads went under the spring and over the axles and the new U-bolts held everything in place.

Wiring and Lights
With the springs taken care of, my next project was replacing the wiring. While removing the old wiring, I decided to go the whole route and replace the lights as well. My tried and true boat trailer parts store had a wiring kit available for a trailer my size. It contained all the necessary wiring as well as the trailer plug and very good directions.

One of the problems with the old wiring was that it was exposed to the weather, which contributed to its deterioration. It was also too easy to inadvertently snag the exposed wiring. To avoid those problems and make a neater installation, I placed all the wiring in split black plastic wire conduits. These are available in various sizes from your marine store. I held the conduit in place with nylon wire clips screwed into the trailer frame.