A Step-by-Step Approach:
The Basic Parts/Systems of a Trailer

Tires
Here's what to check with regard to tires:

• Inflation: Maintain recommended inflation levels. Properly inflated tires will help the boat and trailer track better when under tow. Under-inflated tires can overheat and blow out, causing an accident or damage to the boat and trailer.
  
• General condition: Tires with insufficient tread depth should be replaced. Dry-rotted tires are susceptible to blowouts and leaks, and also should be replaced.
  
• Spare: Always carry a spare and make sure it is in good condition and properly inflated. Without a spare, you may have to leave your boat unattended beside the road which makes it a target for theft or vandalism.
  
• Jacks/tire irons: The jack and/or tire iron that comes with your vehicle may not be appropriate when trying to change a trailer tire on the road. You may need a scissors or hydraulic jack. Check it before you hit the highway, and carry the necessary emergency equipment with you.

Rollers
To prevent damage to the hull of your boat when loading or off-loading, make sure the rollers or bunks roll or pivot freely if they are not permanently adjusted to your specific vessel. Lubricate or replace if needed.

Bunks
Ensure your bunks are properly padded and look for wear on the surfaces.

Trailer frame
Inspect the frame for any corrosion, particularly the U-bolts that hold the axle to the frame. Even though many of today's trailers are made from galvanized, aluminum or stainless steel components, they are still susceptible to corrosion from harsh environments and from wear and tear. If you suspect there may be a problem, replace the part(s) or consult your local trailer expert.

Tie downs
The boat should be securely attached to the trailer at several points. The bow eye of the boat should be attached to the winch, and a safety retaining strap should be used to ensure that the boat does not roll off the trailer. Additional side or transom tie-downs should be used to further secure the boat for travel.

Tongue weight and load distribution
The trailerable weight of your boat also includes the motor, fuel (approx. 7lbs./gallon) and boating equipment. Your boat will track better on land and in the water if the weight is properly distributed. Remember, your boat is not a cargo box. Don't exceed the trailer's weight limits.

Also, tongue weight, or the downward force of your trailer on the hitch of the vehicle, should be 5 - 15% of the fully loaded boat weight for proper balance of the load. Tongue weight and the locking lever together hold the trailer down on the car. One trailer manufacturer we consulted said they found 7% to be an optimum figure for their trailers. Don't forget to check the maximum tongue and tow weights for your vehicle/hitch.

Registration/inspection/local trailer laws
Last but not least, make sure your stickers and registration are up to date and that your rig complies with all local laws and regulations. Getting a ticket for a minor oversight can put a crimp in a wonderful day of boating with family and friends.

These are just a few tips to help you get ready for the new season. Regular cleaning and maintenance during the season will also add to the life of your trailer and keep you safe as you transport your boat to and from your favorite boating locations. Trailering might not be fun, but it's a critical element. Enjoy a hassle-free season!

Brakes
Most trailers for smaller boats (boats less than 20' in length) do not have any type of brake system. This greatly reduces your maintenance requirements. Larger trailers, however, may have a surge brake system.

When you do your brake check-up:

• Ensure the reservoir (in the coupler) is full.
  
• Check all brake lines and fittings for leaks and corrosion. Look for chafing where brake lines enter/attach to the trailer frame.
  
• Examine the brake assembly. Inspect the brake pads for even wear. Replace worn pads. Check for corrosion and clean as necessary. There is a hidden area where corrosion often forms just inside the rubber boots of the brake cylinders. Corrosion on the cylinder walls prevents the pistons from traveling freely, and can cause your brakes to fail to activate or retract (creating a potential lock-up situation). Corroded or pitted cylinders should be replaced. If the entire brake assembly needs to be replaced, consider galvanized/aluminum backing plate assemblies. These are available at most trailer or RV shops.
  
• Test the brakes' operation. Block up the trailer, spin the tires and activate the surge latch. If the wheels fail to brake or release, a complete teardown or trip to a repair shop may be needed.
  
• Flush the brakes. Brakes should be flushed with fresh water after each use, regardless of whether the trailer was submerged in salt or fresh water.

Wheels and wheel bearings
Wheel bearings should be repacked yearly. Here's what to do:

• Inspect the bearings for rust or dirt.
• Clean and/or replace if needed.
• Check spindles for any signs of pitting or corrosion.

Many smaller trailers come equipped with "bearing buddies" - an easily serviceable bearing assembly with a grease fitting. An occasional squirt or two of fresh grease into the fitting maintains lubrication and helps push out any residual water. Take care not to overfill the grease fitting - this could push out the "o" ring seals.

Lug nuts should be checked for tightness, and studs should be free of corrosion to make changing a trailer tire on the road easier.

NOTE: If you'll be taking a long trip, consider carrying a grease gun with you to periodically re-lube the bearings. High temperatures and high speeds can cause grease to break down much sooner than quick trips to the local boat ramp does.

Couplers

• Inspect the coupler for any unusual wear or damage.
• Keep it clean and lubricate the ball cavity with a light coat of grease.
• Use a cotter pin, bolt or padlock to hold the latch down to prevent it from coming loose and to discourage theft or vandalism.

Safety chains
Inspect the safety chains, hooks and fastening points for wear or corrosion. Replace if needed.

Safety chains should be crisscrossed under the trailer tongue to prevent the trailer from hitting the ground in the event it pops off the ball hitch.

Lights
Before hitting the road, do a simple light check.

After connecting the trailer to your car or truck, have someone stand behind the trailer and confirm brake, turn signal (rear and side) and tail light/running light operation.

If one or more of these lights don't work, here are some likely problems and solutions:

• Problem: Burned-out bulb(s) or burned-out filament in a bulb
  Solution: Replace as needed.
• Problem: Corrosion or oxide film on the bulb sockets / light assembly connections, vehicle-to-trailer connector(s) or splices
  Solution: A quick cleaning with emery cloth or a wire brush may do; severely corroded parts should be replaced.
• Problem: Improper ground between vehicle and trailer
  Solution: Troubleshoot with a volt meter and isolate the problem or take the trailer to a repair shop for diagnosis and treatment.
• Problem: Chafed wires shorting out to vehicle or trailer frame
  Solution: Visually inspect all wiring and check the condition of the insulation, especially the points where wiring exits the trailer frame. Repair chafed wires with electrical tape or replace as needed or take trailer to a repair shop.