Changing Your Boat Trailer Tyre: What You Need to Know

Even an immaculately maintained boat trailer isn’t immune to the odd flat tyre, and when you get one chances are you won’t be in an ideal place, either. Knowing how to change a tyre is one thing, but there are some very important aspects to changing your boat trailer tyres that we need to cover.

Safety first (second and third)

1. Ideally, move your boat trailer to a hard, level surface such as a garage or driveway.
2. If you’re on the road, find a safe place to pull over. Try to do so completely off the road, in an emergency lane or driveway. Make the call – if getting off the road is not an option you may have to change the tyre immediately. Otherwise, you’ll need to ‘nurse’ your boat trailer to a safer location.

3. Before jacking up your boat trailer, ensure that your boat is properly secured using tie downs. Your boat is not secured safely if only tethered by the marine winch.

4. Don’t take chances – if you’re on the road, never assume that drivers can see you, even during the day. Switch on your hazard lights before exiting the towing vehicle. If they’re available to you, wear a safety vest or hi-vis shirt and put out your safety triangle.

5. Keep children in the towing vehicle, and if another adult is present, have them assist and act as lookout.

Jacking

There’s a range of jacks out there, but in this guide we’re sticking with a classic bottle or scissor jack.

1. Optionally, bring the flat tyre up onto a block to make jacking easier, especially with a nearside flat, as cambered roads will tilt the boat trailer towards the kerb.

2. Engage both towing-vehicle and boat-trailer handbrakes. It is unsafe to just put your towing vehicle in gear or in park. For added safety, keep the boat trailer on the tow bar at all times.

3. Chock up the tyre(s) opposite the flat tyre.

4. With the coupling hitched to the tow bar, the boat trailer’s ideal jacking point can vary according to the design of the chassis. However, it is likely that the chassis is mounted too high for many portable jacks. Considering this, the ideal jacking point is directly on the axle. In the case of a tandem-axle boat trailer, choose the axle of the tyre that requires changing.

Note: Never use a jack on the boat trailer’s lateral cross-members, as they are likely to be at an angle to the ground. This arrangement will almost certainly lead to slipping under load.

5. If the ground is soft or uneven, use a base plate (dedicated or otherwise) to ensure the jack remains steady.

6. Extend the jack to meet the jacking point, ensuring that it is as close to the hub as possible. Continue until you feel the jack take on the boat trailer’s weight.

7. Just before the tyre leaves the ground, untighten the wheel nuts with the wheel brace.

8. Jack the boat trailer until the tyre clears the ground and the wheel can be removed easily – enough to fit an inflated spare.

9. Warning: Never get under your boat trailer while it is jacked up.

Fitting the spare

It’s just like fitting a car spare.

1. Fit the spare to the hub. If you used a block at the beginning, remove it. You’ll notice there’s now plenty of room to refit the wheel without further jacking.

2. Hand-tighten the wheel nuts diagonally.

3. Lower the boat trailer, keeping the jack in place.

4. Using the wheel brace, tighten the wheel nuts firmly, moving in a diagonally opposed pattern until all nuts are tightened. Use a torque wrench to ensure the correct tension.

5. Un-chock the far-side wheel(s).

While changing your boat trailer’s tyre roadside isn’t recommended, it’s sometimes your only option. Remember that your safety and that of your occupants is your primary concern, so take it easy and take your time.

Once you’re back on track have a look at a step-by-step guide to launching your boat.