Repair & maintenance guides
Plain-English, step by step, written for owners. Pick your engine to see the guides that apply to it.
24 of 459 guides

Boat Ramp Traction with a 2WD or Front-Wheel-Drive Vehicle: Stop Spinning, Stay Dry
Spinning tires on a slick ramp are embarrassing at best and dangerous at worst. Learn how rear-wheel, front-wheel, AWD and 4WD vehicles behave on a ramp, how to set up weight and tires, when to use 4WD Low, how to keep the vehicle from sliding in, and what to do if you get stuck.

Electric-Over-Hydraulic and Electric Trailer Brakes: Controller Setup, Breakaway and Care
Why most boat trailers use surge or electric-over-hydraulic (EOH) brakes instead of plain electric drums, how to pick a compatible in-cab brake controller and set its gain, how to test the breakaway switch and battery, and how to keep the system working around saltwater.

Get Your Boat Ready for the Road: Pre-Trailering Checklist
Most trailering trouble starts in the driveway: an engine left without support, a loose strap, a cover that balloons at 60 mph, gear that blows out or tongue weight that makes the rig sway. Work through this checklist before every trip and do a quick walkaround at each stop.

How to Adjust and Replace Trailer Bunks and Rollers So Your Boat Sits Right
Set up your boat trailer so the hull is supported in the right places: bunks and rollers clear of the strakes, the transom fully supported, the bow snug against the winch stop and the weight balanced on the tongue. Also covers replacing rotten bunk boards and worn carpet or rollers.

How to Check and Care for Boat Trailer Surge Brakes
Understand how the hydraulic surge brakes on your boat trailer work, check the fluid, use the reverse lockout correctly and rinse salt out of them after every dunk. Simple habits that keep the brakes from seizing, dragging or failing when you need them.

How to Choose, Install and Adjust Trailer Guide-Ons (Posts or Bunks)
Add or tune the side guides on your boat trailer so the hull lines up in wind and current, the posts stay visible at the ramp and nothing rubs the gelcoat on the road. Covers post vs. bunk guide-ons, lighted posts, mounting height, side clearance and yearly care.

How to Fix Boat Trailer Lights That Flicker, Dim or Don't Work
Track down the real cause of dead or flickering trailer lights, from a bad ground to a corroded plug, and fix it so the repair lasts. Working brake, turn and tail lights are required by law and keep the driver behind you from rear-ending your boat.

How to Identify Your Boat Trailer Axle and Order the Right Parts
Find your trailer's VIN plate and axle lot number, take the key measurements (hub face, spring centers), read the numbers on your bearings and seals, and figure out the brake and hub type, so the parts store sells you parts that actually fit.

How to Inspect a Used Boat Trailer Before You Buy
A worn-out trailer can turn a good boat deal into hundreds or thousands in repairs, or a breakdown on the way home. Walk through the capacity plate and VIN, frame, axle and springs, hubs, brakes, tires, lights, coupler, winch and bunks, and the title paperwork before you hand over the money.

How to Inspect and Repack Boat Trailer Wheel Bearings
Check, clean and repack your trailer's wheel bearings so a seized hub does not leave you stranded on the highway. Boat trailers get dunked in water every launch, which makes their bearings fail far more often than those on dry utility trailers.

How to Inspect and Replace Your Bow Eye and Transom Eyes
Check the bow eye and transom tie-down eyes for rust, loose nuts and missing backing plates, and replace and reseal them properly, because a failed bow eye can let the boat slide off the trailer.

How to Inspect and Use the Trailer Winch, Strap, Tie-Downs and Safety Chains
Check the winch, strap or cable, bow safety chain, transom tie-downs and the safety chains to your vehicle, and learn how each one is meant to be used. These parts keep the boat on the trailer and the trailer behind your truck.

How to Inspect Boat Trailer Axles, Leaf Springs and Hangers
Check the parts that actually hold your boat off the road: the axle tube, leaf springs, hangers, shackles, bushings and U-bolts (or the rubber torsion axle on newer trailers). Learn what rust-through, broken leaves and worn shackles look like, how uneven tire wear points to a bent axle, and when it's time to replace instead of patch.

How to Inspect, Inflate and Replace Boat Trailer Tires
Check your trailer tires the way the pros do: the right type (ST), the right load range, the right cold pressure, and an honest look at their age. Tires are the number one reason boat trailers end up on the side of the highway.

How to Launch and Retrieve Your Boat Alone
A repeatable routine for putting a trailer boat in and taking it out by yourself: what to do in the staging area, how to rig one long line so you can control the boat from the dock, when power loading is off-limits, and the safety habits that keep you, your boat and the next boater out of trouble.

Is My Vehicle Rated to Tow This Boat? Towing Capacity, GCWR and Tongue Weight Explained
The towing number in the ad is only one of several limits. Learn which ratings matter (towing capacity, GCWR, GVWR, axle and tongue limits, hitch class and ball rating), how to weigh your real rig at a truck scale, and when you need trailer brakes and towing mirrors.

Replacing a Boat Trailer Axle: When You Need One and How to Order the Right Size
A bent, rusted-through or undersized axle can't be fixed with new bearings. Learn the signs, the difference between straight, drop and torsion axles, the measurements a supplier needs (hub face, spring centers), what to specify for saltwater, and why this is usually a trailer-shop job.

Roadside Trailer Repairs: Carrying a Spare Hub and Changing a Hub or Tire Safely
Why a pre-greased spare hub and a real spare tire belong in every boat-trailer kit, how to pick the right ones, and how to change a failed hub or a flat on the shoulder without getting hurt: getting off the road, warning triangles, chocks, frame jack points, a lug wrench that fits, and the checks to make afterward.

Tow Vehicle Maintenance for Boat Owners (Transmission, Differential, Brakes, Hitch)
Keep the truck or SUV that pulls your boat ready for the job: follow the severe-service schedule, protect the transmission from heat, check the rear differential for ramp water, keep brakes, tires, hitch and wiring in shape, and rinse salt off the underside after every saltwater launch.

Tow Vehicle Rear Differential Care: Ramp Water, Milky Gear Oil and Limited-Slip Additive
Backing the truck's rear axle into the water at the launch ramp can pull water into the differential through its vent. Learn how water gets in, how to keep the axle dry, how to drain and read the gear oil, why limited-slip axles need friction modifier, when to change the fluid, and when the differential needs a shop.

Towing a Wide or Heavy Boat: Width Limits, Oversize Permits and When to Hire a Hauler
In most states a boat or trailer wider than 8 feet 6 inches (102 inches) is a wide load that needs a permit, and some loads also need flags, signs, lights, set travel hours or escorts. Learn how to measure your rig, find each state's rules, get the permits and decide when a professional transporter makes more sense.

Trailer Tongue Jack and Coupler Care: Grease, Adjust and Know When to Replace
The tongue jack and coupler take a beating from weight, road grit and launch-ramp dunking. A few minutes of cleaning and grease a couple of times a season keeps the jack cranking smoothly and the coupler locking tight on the ball, and tells you when either part is worn out.

Transom Savers and Motor Supports: How to Trailer Your Outboard or Sterndrive
Potholes and driveway dips put real load on the transom, the tilt system and the engine bracket. Learn when engine makers want a support, why the tilt support lever is not one, how to choose and fit a transom saver or trim-ram support, and what goes wrong when it's fitted badly.

Upgrading Boat Trailer Hubs: Grease-Through Spindles, Oil Bath, Protectors and Pre-Packed Kits
Choose the right hub setup for how you use your trailer, swap in a pre-packed hub kit, adjust it correctly and know when the axle itself is the real problem. Better hubs mean fewer roadside bearing failures and less time with greasy hands.
Safety: BoatMend is for information only and does not replace a certified marine technician. You are responsible for your safety and your boat. Read the full disclaimer.