Maintaining Your Sailboat Trailer

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Updated July 06, 2017

Too many trailerable boat owners ignore their trailers, leading to breakdowns on the road and potentially dangerous situations. Routine inspections and maintenance keep your trailer safe and working and can extend its life for many years.

Inspection and Action Steps Before Use

Grease the wheel bearings before use (see below)
Check that tires are properly inflated (usually around 50 lbs pressure, not 30-35 like most auto tires) and wheel lug nuts are tight; check tire tread for wear and sidewalls for spider cracks that may indicate dry rot
Inspect the whole trailer for cracks or severely rusted areas that may have become weak, including the springs and axles
Check rollers and runners for cracks or breaks; ensure rollers are clean and have not locked up
Check the winch's operation and the condition of the strap or cable
Check that the trailer ball is tightly mounted and the right size for the hitch; clean any debris from both before seating the hitch on the ball
Ensure that the hitch coupler is locked in place and secured with a bolt or lock
Cross the trailer safety chains before securing them to the tow vehicle (the crossed chains "cradle" the trailer hitch if it comes free from the ball)
Ensure the trailer tongue jack is completely rotated up and locked in place
Ensure the trailer lights are working, including brake lights and turn signals

If the trailer has brakes, test that they are working
Avoid overloading the trailer by removing heavy items from the boat and transporting them inside the tow vehicle (many boaters remove outboards)
After haul-out, remove any drain plugs to drain bilge or hull water

Routine Maintenance

Check the trailer for nongalvanized parts (U-bolts, nuts, wheel lug nuts, add-ons) and spray them with a rust inhibitor like Corrosion X
After immersion in salt water, rinse the trailer with fresh water; if practical, dunk the trailer in a fresh water lake on the way home (also run the motor to flush it with fresh water)
If the trailer is painted rather than galvanized, check carefully for rust; remove rust and repaint as needed; use auto wax to help protect the paint
In hot, sunny areas, spray the outside of the tires with a product like Armor-All to prevent dry rot caused by heat

The Wheel Bearings

Because the wheel bearings are the most vulnerable part of a boat trailer, take the time to keep them well greased and protected from the elements.

If the trailer does not already have them, install "bearing buddies" on each hub; these help protect the bearings from water and have a grease nipple for quick application of bearing grease
Install dust covers over the bearing buddies
Add bearing grease before starting out - but not so much that the rear seals are pushed out; be sure to use marine grease, especially in salt water

If the trailer has not been used recently, stop after a short distance of towing to check the hubs for heat, which indicates a bearing problem. If the bearings heat up even when greased, repacking is probably necessary. You can do this yourself if you are competent mechanic; otherwise go to a professional.

Spare Parts to Carry

Fully inflated spare tire of the right size
Grease gun and extra grease
Road flares and flashlight if towing at night
Spare fuses and light bulbs for lights
Long-distance towers may choose to carry a spare wheel hub

Tips for Safe Trailer Use

Always use a good tie-down to secure the boat to the trailer
At stops when towing, visually check the trailer and boat, check the winch strap and tie-downs are still tight, and feel the wheel hubs for heat that indicates a bearing problem
After arriving at the water, allow bearings to cool before immersing the wheels in the water (sudden contraction with cold can suck water into the bearings)
Before launching the boat, unplug the trailer lights