Trailering Tips AFTER LAUNCH, DRY OUT During long drives wheel hubs heat up and bearing seals expand. While launching causes water to migrate into the hub, parking the trailer allows the hubs to cool down and seals contract to trap water in the bearings which leads to failure. To preserve bearings after launching, don’t immediately drive to the parking area. Instead, drive around the block to dry all components in your trailer’s braking system. BEARING INSPECTION To check the wheel bearings: working on a level surface, block the tire wheels, place a jack under the axle and individually raise each wheel clear of the ground. Place your hands on the outside edge of the tire and try to rock the wheel by pushing on one side and pulling on the other. Spin the wheel and listen for noise or roughness. If the trailer has brakes, make sure the brake shoes are not dragging. The wheel should spin freely and not rock. Inspect the wheel bearings at least once a year. If hubs are not rotating smoothly, replace bearings. Trailer hub bearing kits help simplify this procedure and are available to fit most spindle dimensions. BRAKE CHECK To check brake fluid level, remove the cap on the actuator housing. If fluid is about 1/2" (12 mm) below the top, add fluid. Use only fluids specified by the trailer manufacturer. Inspect brake shoes and rear seal.
Store all wooden trailerable boats on bunk trailers as opposed to roller types. Even some “Tupperware” boats, over time, can develop roller dents permanently impressed into the hull. COUPLER UPKEEP Examine the coupler for rust, cracks and correct clamp adjustment. Lightly oil all moving parts such as the hand-wheel threads and the pivot points in the latching mechanism. Give them a shot of a moisture-displacing lubricant to prevent corrosion. Don’t forget to check the safety chain for damage. Inspect the jack stand and lubricate. CURE FOR RUBBER RUB OFF To prevent rubber bow stops on trailers from transferring black marks to the hull when they’re winched tight against the bow, coat them with an acrylic clear coat finish, such as Captain Phab Clear Coat. A water-based product, it’s available in a glossy or satin finish. As it wears off with use, the bow stop will need to be recoated periodically. Use it also on brass and other metals to prevent corrosion. A light coating sprayed on vinyl striping, serial numbers and graphics protects them when washing or waxing the hull. CUSTOM FIT The boat should be resting against all trailer supports. If not, adjust the height of the bunks and rollers to fit. To reduce friction, grease shafts on the rollers with a medium weight oil. Examine the runners and carpeting. Replace if worn.
Most problems with trailer lights and wiring are a result of poor installation. Carefully inspect wiring terminals and replace all butt connectors and any corroded ones with marine-rated terminals, preferably heat-shrink, or moisture-proof connections with heat-shrink tubing. Use plastic holders to support wiring as needed so it doesn’t droop and replace all steel holders before they corrode. FRAME WORK Examine welded joints on the trailer frame for any breaks. Make sure all nuts and bolts are tight. Inspect the axle springs and attaching U-bolts for cracks and rust. For painted steel trailers, sand or wire brush any rust spots or chipped or flaking paint. Prime if necessary and apply a rust-inhibiting paint. Touch-up rust spots on galvanized trailers with cold galvanizing spray paint. Protect your trailer with a quality marine-grade wax. GREASE MATTERS Grease the wheel bearings following the manufacturer’s instructions. Use a certified water-resistant marine trailer bearing grease and a hand gun. Never use automotive grease as it is not water-resistant. Do not grease when the hub is cold as too much grease flow may damage seals and brake shoes. Overgreasing bearing protectors can cause the seal to fail.
Lack of lubrication is the primary cause of bearing failure. Rather than run bearings to failure, repack bearings once a year, regardless of the distance traveled. When packing bearings, don’t just apply grease to the rollers. Rather, place a glob of grease in your hand and keep dipping the bearing into the grease until grease flows out the other side. (Professionals use bearing packers.) Put a little smear of grease on the outside then insert into the cup. Use only Kendall or Penzoil grease, mainly because when it gets hot it doesn’t melt. GREASE THAN LAUNCH Check bearing protector lubricant levels when the hubs are warm. Manufacturers recommend that you check just prior to launching to be sure hubs are full of grease when the axle is submerged. HUB PROBE The only sure way to check bearings is to either spin the wheel or holding hands on the rim, twist the tire feeling for any sideways movement. A slight grinding sound or a wheel with play warns of imminent bearing failure. When a bearing fails it seizes, the tire stops turning and, if towed, will blow to pieces.
For boats equipped with power trim, a motor support bracket will help prevent damage to the transom and hydraulics by absorbing road shock and vibration. It also protects the skeg by elevating the lower unit. The V-shaped end attaches to the engine’s lower unit and the inboard end is held in place on the trailer. Different models support motors up to 150 hp. LOAD ANGLES For maximum performance and safety, all trailers are designed to be towed level. With trailer hitched to your vehicle, stand back and eyeball the hitch angle. If the trailer sits too high at the front, tongue weight will be too light. This condition transfers weight and extra wear to the back axle, a situation more critical on tandem trailers, and the trailer is apt to sway. Conversely, a too-heavy tongue weight results in the rear of tow vehicle and front of trailer positioned downwards. With heavy loads, this angle is more pronounced. A tow vehicle that rides low enough on the back end to raise the front suspension results in skiddish steering and perhaps front-end sway. Adjusting hitch angles requires either aft or forward shifting of gear in the boat, moving the load in the tow vehicle or repositioning boat on the trailer.
If you cruise on waters that are subject to strong currents or crosswinds or launch at a particularly steep ramp, you should consider installing load guides. These handy braces center the boat on the trailer when loading. They come in all shapes and sizes, from a crude but effective length of ABS pipe (topped with a cap to prevent filling with water), to vertical posts with rollers, to a color-matched carpeted wood bunk. All easily bolt directly to the side frame. Upright posts also double as guides, helping to align the boat when backing up or loading, particularly at steep and deep launch ramps. Some models stow flat when the trailer is empty.
To guard against theft of your trailer, or the hitch assembly when not connected to the trailer, drill a hole in the end of the hitch pin and attach a heavy-duty lock. OUTBOARD BRACE Trailering can exert significant forces on your outboard that can cause damage to the trim and tilt mechanism and to the outboard itself. Always trailer with the motor in the fully lowered position (if there’s clearance), or use a transom support bracket such as a wood block or other commercially available bracket. PRE-SEASON INSPECTION Check your electrical system at least annually. Trace the wiring from the tow vehicle to the taillights and look for bare wires, cracked insulation or corroded terminals. Check that the white ground wire is connected to the trailer frame. Replace all worn or damaged parts. Make sure all trailer, brake and turn signal lights are operating. Replace burned-out or corroded bulbs. Apply a light coating of water-resistant grease, petroleum jelly or moisture-displacing lubricant to all plug prongs, bulb sockets, wire splices and ground connections. PRESSURE TEST Check tire pressure when tires are cold since hot tires increase pressure, depending on distance traveled. Traveling 93miles (150km), for example, increases pressure by about 7lb (3kg).
Since backing up automatically puts pressure on surge trailer brakes, units have on the hitch either a lock-out slide or require inserting a 1/2" (12mm) pin (not included with the brake unit). You’ll find information on brake disengaging in the hitch operating instructions; another reason to read your owner’s manual. SALT-PROOFING TRAILERS Boat trailers used in saltwater are commonly galvanized for corrosion protection but springs, hubs, winch gears and swivel jack soon start to rust. A product generally referred to as “open gear lube” can prevent this. Used by marine salvage and construction industries, this almost tar-like lube is sprayed on clean metal. It contains a carrier that penetrates the spring leaves and then evaporates leaving a flexible, waterproof, lubricating coating. It is available from many industrial cleaning suppliers, particularly around harbors and industrial areas. It’s a mess to put on but one application will last five years, so you’ll at least double the life of your trailer parts. STABILIZING THE LOAD If the trailer starts to sway when towing, reduce speed. If sway is caused by too much tongue weight, then rearrange items carried in the boat to move weight aft or move the boat aft on the trailer. If, however, it’s a factor of wanting to drive fast, then you’ll need to stabilize the trailer. Stabilizer bars lift up the rear of the tow vehicle and transfer the weight onto the front tires. Because of this weight shift, their installation is recommended when towing with all large front-wheel drive vehicles. SUSPENSION BOOSTER Balancing tongue weight is a simple task with small boats but more complex with larger rigs that often requires add-ons. The best devices to equilize weight when towing heavy boats with a pickup truck are load boosters. Easily mounted between the truck frame and the axle, these solid rubber “bumpers” support the extra hitch weight. This means the truck remains level, doesn’t sway or bottom out on the springs. When unloaded, the rubber bumper doesn’t touch the frame so the ride is unaffected.
How do you know when to replace tires? First, closely inspect your tires. Early stages of dryrot damage are barely visible (top) compared to a severely decayed tire (bottom) that on a hot summer’s day driving at highway speeds would likely blow within minutes of use. Many new trailers are now standard-equipped with radial tires. Though more expensive than bias-ply tires, they can withstand more heat and support more weight. When upgrading, purchase radials and preferably tires specially built for trailers (i.e. Carisle brand). TIRE SCAN Check tire pressure (when tires are cold) and tread depth in all tires including the spare. Look for any visible cuts or bulges. Check the lug bolts for tightness (do this prior to every trip).
Five to 10% of your trailer’s Gross Vehicle Weight or GVW (boat, gear and trailer) should be supported by the trailer coupling ball when the tongue is parallel to a level surface. For example, if the GVW is 3,000 lb (1,350 kg), the weight on the coupler should not exceed 300 lb (135 kg) or be less than 150 lb (67.5 kg). With smaller boats you can check tongue weight with a bathroom scale. Place a wood support between the coupler ball cup and the scale. Use a level to ensure the trailer is horizontal to the ground and adjust with plywood shims, if necessary. For larger boats, find a trailer supplier with a scale. If you reposition the boat on the trailer, you’ll need to recheck tongue weight. A slight shift in positioning can alter tongue weight enough to cause handling problems. TOO MUCH GREASE? If you are continually adding a lot of grease to a hub, chances are the rear (inner) seal is probably leaking grease onto the axle brakes (if equipped) and letting water in. Grease leaking onto the brake linings may cause the brakes to malfunction. Trailer manufacturers recommend replacing grease seals once a year, preferably before storing for an extended period of time. Replacement requires removing the complete hub assembly from the spindle. TOWING POWER Many boaters arrive at a launch ramp only to discover a dead battery and that they can’t start their engine. An easy hookup used on most RVs uses juice from the tow vehicle to charge the boat battery. Connect a wire from the positive post of the tow vehicle battery to an unused terminal on the trailer light connector and wire this to the boat’s positive battery terminal. Use at least a 12 AWG wire and splice in a 30-amp fuse for safety. The trailer ball supplies the ground (negative) connection and completes the connection. TRAILER SETUP A trailer that is not correctly setup can damage the trailer and boat. An improperly aligned trailer can cause frame and roller damage, increase loading on the winch, fishtailing on the highway and general damage to the boat. Damage to the boat’s hull, referred to as “wows and hooks,” is often the result of incorrect support. If the boat is loading off center, check the following: 1. For roller trailers, the boat should rest evenly on all rollers. If needed, adjust only the tongue-keel rollers and side rollers so that all parts of the hull come in contact with each roller. The boat’s transom should rest on the rear-most roller. 2. For bunk trailers, the long, straight bunks should evenly distribute the load. Adjust the bunks if one side is higher than the other or does not fit the boat properly. The boat’s transom should be even with the end of the bunk. 3. If equipped with bow and center supports, make sure that each connects with the hull. To prevent bouncing, keep tie-downs tightly fastened. 4. Adjust the height of a mechanical or electric winch so the winch line is level with the bow eye of the boat, which is just below the bow stop roller or vee block. TROUBLESHOOTING HYDRAULIC BRAKES Brake linings become water soaked when submerged in water. Suppliers recommended that you tow the trailer a short distance then apply the brakes before parking it. This “dries out” the system and extends the life of the brake linings. Saltwater can cause severe damage to drum brake parts. A brake flush kit will help resist corrosion. Surge brakes usually do not have an automatic brake lining adjustment system and require regular adjustments to compensate for wear. WINCH BASICS Clean the winch and check for corrosion. Lubricate the drive shaft bearings of a mechanical winch regularly with oil and apply heavy grease to the gears and reel shaft frequently. Replace a frayed winch rope, cable or webstrap. Consider replacing wire with nylon web (seat belt) strapping; there’s less friction and it won’t rust. Check all tie-down straps for wear. X MARKS THE SPOT The positioning of your boat on the trailer directly effects tongue weight when towing. Bow stops help determine the placement, but often the boat rides higher, particularly when the trailer is buried deeper than usual due to a ramp with a long grade. To correctly position the boat every time you load, mark the spot where the bow roller rests against the boat with a dab of nail polish. |
ELECTRICAL COMPONENTS 
GREASE PACK 
LIFT AND SUPPORT 
LOAD GUIDES 
LOCKING HITCH 
REVERSE POWER 
TIRE FATIGUE 
TONGUE WEIGHT ©2009, Boat Owners Association of The United States. All Rights Reserved.
