Caravan sway is scary — but it’s also usually fixable. Most sway starts small and builds because something is off in your setup: weight balance, towball weight, tyre pressures, hitch height, speed for conditions, or loads shifting mid-trip.

This guide is designed to be practical: what sway is, what to do if it happens, and how to stop it happening again with real-world setup and loading habits.

Important: Always stay within your tow vehicle and caravan limits (ATM / GTM / GVM / axle ratings / towball limits / towbar and hitch ratings). If you’re unsure, book a weigh-in (weighbridge or mobile weigh service) and get professional towing advice.

In this guide

• What sway is (plain English)
• What to do immediately if sway starts
• Why sway happens (most common causes)
• How to prevent sway (setup + habits that work)
• Load placement rules (simple + practical)
• Towball weight: targets, red flags, and how to fix it
• Using water tanks to fine-tune stability
• Tyre pressures (starting points + what to change if it sways)
• Tow vehicle setup (suspension, hitch height, WDH notes)
• Driving technique (stability habits)
• Quick troubleshooting checklist
• After a sway event: what to check
• When to get professional help
• Quick FAQs
• Fast pre-trip checklist

What sway is (in plain English)

Sway is an unstable side-to-side movement of the caravan that can build quickly at speed. Think of it like a shopping trolley that starts wobbling: the faster you go, the harder it becomes to control.

Sway is not the same as normal “movement” over bumps. A stable rig will still move with road undulations, but it will settle quickly. Sway is when the van starts “wagging” behind the vehicle and the motion grows rather than settles.

Early warning signs:

• A light “tail wag” sensation that doesn’t disappear
• The steering starts to feel vague or “floaty”
• You feel the tow vehicle being gently pushed side-to-side
• It gets noticeably worse when a truck passes or when you hit open/windy sections

Why it matters: once sway escalates, the forces increase fast. The goal is to catch it early, reduce the triggers, and then fix the root cause before you continue.

What to do immediately if sway starts

Why sway happens (most common causes)

Sway is almost always the result of instability plus a trigger. The instability comes from weight balance or setup, and the trigger is often wind, trucks, bumps, or speed.

1) Rear-heavy loading

If too much weight sits behind the axle group (or on the rear of the van), the van can behave like a pendulum. The rear weight “wants” to swing, and at speed it’s harder for the tow vehicle to dampen that motion.

2) Towball weight too light

Low towball weight means the van isn’t planted at the hitch, so it can wander and oscillate more easily. This is one of the most common contributors to sway.

3) Speed for conditions

Even a good setup can feel sketchy if speed is too high for wind, wet roads, or heavy traffic. Sway forces increase quickly with speed.

4) Tyre pressures and tyre condition

Tyres are part of your suspension system. Too low can create heat, flex and “mushy” instability. Too high can reduce grip and make the rig feel nervous. Worn or mismatched tyres can worsen the problem.

5) Crosswinds and truck turbulence

Passing trucks create pressure changes that can push/pull your van. Crosswinds can add a constant side load. If your setup is borderline, these triggers expose it immediately.

6) Tow vehicle setup mismatch

Soft rear suspension, poor shocks, incorrect hitch height, or being close to rear axle limits can reduce control. The tow vehicle needs to remain composed, level and predictable for stable towing.

7) Loads shifting while driving

Loose items, poorly packed storage, or water moving around can shift the centre of gravity mid-drive. That can turn a “fine” setup into a swaying one without warning.

How to prevent sway (best-practice setup + habits)

Most “no sway” towing comes down to four pillars:

1. Correct weights (especially towball load and axle loads)
2. Smart loading (heavy low, near axles, not at the rear)
3. Correct tyre pressures (tow vehicle + van)
4. Correct towing attitude + tow vehicle control (level or slight nose-down, suspension that can manage the load)

Best practice approach: treat your travel setup like a “recipe.” Once you find the stable combination (gear locations, water levels, tyre pressures), repeat it every trip and only change one variable at a time when testing.

Load placement rules (simple + practical)

Golden rules:

• Heavy low: heavy items down low = lower centre of gravity = more stable.
• Heavy near the axles: weight close to the axle group is easier to control.
• Avoid rear-loading: rear weight reduces towball load and increases pendulum effect.
• Secure everything: moving loads change balance while you drive.
• Re-check after changes: new accessories can alter handling dramatically.

Practical examples (what owners commonly do):

• Good: tool kits, recovery gear, spare parts stored low and near axle line.
• Risky: heavy tubs of gear, generators, firewood, or multiple jerry cans in the rear storage area.
• Risky: heavy items in overhead cupboards (even if the van “feels” fine at first).

Quick tip: If you must carry something heavy at the rear (like bikes), keep everything else as “neutral” as possible — and confirm stability with a weigh-in and a short test drive before a long trip.

Towball weight: targets, red flags, and how to fix it

A stable van needs a positive towball load (enough weight on the hitch to keep the van tracking behind the tow vehicle), but not so much that it overloads the towball limit or unloads the tow vehicle’s front axle and reduces steering/braking feel.

Targets (and the “real” rule)

• Rule of thumb (where limits allow): many setups aim around ~10% of the van’s loaded weight as towball weight.
• Some guidance references a workable range of roughly 8–15% depending on the rig.
• But the rule that matters: stay within your tow vehicle + towbar + hitch + coupling limits and keep axle loads legal.

Red flags your ball weight is too light

• Sway increases with speed or in wind
• Van feels like it “wanders” behind the car
• Truck passing makes the rig noticeably unstable
• You’ve recently added weight to the rear (bikes, storage, extra gear)

Red flags your ball weight is too heavy

• Tow vehicle rear sags excessively
• Steering feels lighter than normal
• Front tyres feel less planted in corners or braking
• You’re near or over towball rating / rear axle limit

How to fix ball weight (without guessing)

1. Weigh it loaded (as you actually travel): towball weight + axle weights if possible.
2. Move weight forward and towards the axle group (not simply “more weight anywhere”).
3. Reduce rear loads (rear carriers, heavy tubs, rear storage).
4. Re-test (short test drive in safe conditions; adjust one thing at a time).

Important: don’t rely on a sway control device as the first “fix.” Devices can assist, but correct loading and towball weight is the foundation.

Using water tanks to fine-tune stability

Water is one of the easiest adjustable weights you have. The catch is it can also change during travel, which changes how the rig feels.

How to use water strategically:

• If towball weight feels too light (sway risk): carrying more water in a tank located forward of the axle group can help stability.
• If towball weight feels too heavy: reduce water in forward tanks and (if your layout allows) keep weight closer to the axle group.
• Grey/black water can change during travel — so if you notice stability changing mid-trip, check tank levels and consider how that affects balance.

Tip: once you find a stable “travel water plan,” write it down and repeat it each trip (e.g., “front tank half, rear tank empty” — whatever works for your layout and limits).

Tyre pressures (starting points + what to change if it sways)

Tyre pressures have a major effect on stability because they influence sidewall flex, heat build-up, grip, and how the rig responds to bumps and wind.

Starting points (guide only)

• Hybrid caravans: many owners start around 45–50 PSI, then adjust based on load and tyre rating.
• Tow vehicle: follow the manufacturer’s towing pressure recommendation (often higher than solo driving).

What to do if sway is present

• Confirm tyre pressures cold (before driving) and ensure all tyres match side-to-side.
• If caravan tyres are low, increase pressure slightly within safe limits, then test.
• Inspect tyres for uneven wear, bulges, or damage (all can contribute to instability).
• Check wheel nuts, wheel bearings, and suspension components if you’ve had repeated issues.

Note: the “perfect” pressure depends on tyre construction, van load, and road type. Treat pressure like a tuning tool — but keep changes modest and within tyre ratings.

Tow vehicle setup (suspension, hitch height, WDH notes)

Not all “rated to tow” vehicles tow the same. Stability depends on wheelbase, rear axle limits, suspension control, and how the whole system works under load.

Common tow-vehicle issues that worsen sway

• Rear sag from soft springs (changes geometry and steering feel)
• Worn shocks (reduces damping, increases oscillation)
• Incorrect hitch height (van towing nose-up or excessively nose-down)
• Too much rear cargo in the tow vehicle (can unload the front axle)
• Hitch components not correctly rated or in poor condition

How to improve stability

• Level the rig: aim for van level or slightly nose-down when loaded.
• Upgrade control: quality towing shocks and appropriate spring setup can make a huge difference.
• Use airbags wisely: airbags can help levelling, but they don’t replace proper spring/shock control.
• Reduce rear load: keep the tow vehicle’s rear as light as practical.

Weight Distribution Hitches (WDH)

WDH can help some on-road setups, but they’re not always compatible with off-road couplings or rough terrain use. Always follow the caravan, coupling, and towbar manufacturer guidance and get professional advice for your specific setup.

Driving technique (stability habits)

Even with a great setup, driving inputs matter. Smooth driving reduces the chance of a small instability turning into a big event.

• Respect conditions: wind + wet + traffic = reduce speed and increase following distance.
• Be smooth: gradual steering, gradual throttle, gradual braking.
• Plan overtakes: don’t rush; anticipate truck turbulence and keep a steady line.
• Leave space: more room gives you time to respond calmly if something starts to feel off.

Practical rule: if you’re thinking “this feels a bit sketchy,” slow down and reassess. Sway is often a warning, not a surprise.

Quick troubleshooting checklist

If your van is swaying or feels “light,” work through this in order. Fix the basics first — most sway is solved here.

Step 1: Loading (fast fixes)

• Remove or reduce heavy items at the rear (rear storage, rear carriers, heavy tubs).
• Move heavy items low and closer to the axle group.
• Secure all loose items so they can’t shift while driving.

Step 2: Towball weight and level attitude

• Confirm towball weight (don’t guess).
• Adjust hitch height so the van tows level or slightly nose-down.
• Confirm vehicle and hitch limits are not exceeded.

Step 3: Tyres

• Set pressures appropriate for towing (vehicle + van).
• Inspect tyre condition and wear (replace if questionable).
• Confirm tyre load ratings are correct for the van’s loaded weight.

Step 4: Tow vehicle control

• Check for rear sag, worn shocks, or poor suspension control.
• Reduce rear cargo in the tow vehicle.
• If needed, get a towing specialist to assess suspension/hitch setup.

Step 5: Re-test safely

• Short test drive in safe conditions.
• Only change one variable at a time so you know what improved it.

After a sway event: what to check

After any sway incident, treat it as a “stop and inspect” moment. Even if it settles quickly, it’s worth checking the basics before continuing.

1. Loading: move weight forward and closer to axles; reduce rear loads.
2. Tyre pressures: check and adjust as needed.
3. Hardware: inspect hitch/coupling, safety chains, electrical plug, and breakaway cable.
4. Wheels: visually inspect tyres; ensure wheel nuts are correct torque; watch for heat or unusual smell.
5. Plan: reduce speed and reassess conditions (wind can be a major factor).

When to get professional help

If sway repeats, don’t keep experimenting at highway speeds. A professional weigh-in and towing setup check is cheaper than damage and safer than guesswork.

• Sway repeats even after you correct loading and tyre pressures
• You’re unsure your tow vehicle is suitable for the van’s loaded weight
• You suspect a mechanical issue (tyres, suspension, hitch/coupling wear)
• You haven’t had the rig properly weighed (towball + axle weights)

Quick FAQs

“Should I buy a sway control device?”

Devices can help as an extra layer, but they don’t replace correct loading, towball weight, tyre pressures, and a level setup. Fix the cause first, then consider devices if appropriate for your towing style and conditions.

“Does more towball weight always mean more stable?”

Up to a point, more towball weight can improve stability — but too much can overload ratings, sag the tow vehicle, and reduce steering/braking feel. The target is “enough but legal and controlled.”

“Why did it sway only when trucks passed?”

Truck turbulence is a trigger. If your setup is borderline, the pressure changes expose that instability. Improve the foundation (load placement, towball weight, tyres, and tow vehicle control).

Fast pre-trip checklist (loads + stability)

1. Heavy items low and near axles
2. Minimal heavy gear at the rear (inside or on the back)
3. Overhead cupboards: light items only
4. All gear secured (nothing that can shift)
5. Tyre pressures set for towing (vehicle + van)
6. Van sits level or slightly nose-down when hitched and loaded
7. Brake controller set and tested (including manual override familiarity)
8. Re-check weights after major changes (racks, batteries, extra tanks, vehicle changes)