Routine inspections and maintenance will keep your boat or pontoon trailer safe and working for many years.

Inspection and Action Steps Before Use

• Grease the wheel bearings before use.
• 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.

Source: About.com