Buying A Secondhand Boat Trailer? Learn From My 10 Mistakes!

Buying A Secondhand Boat Trailer

Buying a secondhand boat trailer kind of doesn’t come close to the attention to detail we pay to the boat. Most of us just want to get out fishing. Right?

Well. This is true, at least, for the first time or so…

While understandable, it’s a huge risk. Often the weakest link.

I don’t mind admitting it. I’ve got this wrong twice. There’s a lot to take into consideration.

But some basic steps. Some attention to detail is essential.

We need to start by dialling back the enthusiasm we are feeling for the boat.


Because a secondhand boat trailer may mean the difference between a great purchase and a ruined boating experience.

It may even save a life!

The potential for a major road accident due to a broken or badly worn component is a major concern.

As you’ll discover, when reading this article, I found out the hard way and had more than one lucky escape!

Note with each point mentioned here. A fault, minor or severe, doesn’t necessarily mean the seller is trying to rip you off.

Not everybody is aware of the basics. Some people are selling a deceased estate. In these cases, they genuinely do not know the risks involved in buying and selling a secondhand boat trailer.

Table Of Contents

Secondhand Boat Trailer Bearings

The bearings are quite literally the number one reason for seeing boat trailers broken down on the road.

The bearings literally help the wheels spin. A seized bearing locks up the wheel. The result can be damage to the tyre, at best, or the entire wheel can fly off.

You really do want to avoid that lump in the throat feeling. You’ll find you experience this when your wheel overtakes you on the highway!

Don’t think it can happen to you?

Your boat trailer is getting dunked into water, nearly every time you launch and retrieve your boat. Water corrodes metal. Saltwater is even more corrosive. Without care, it becomes not if – but when.

Bearings Are The Bain Of Secondhand Boat Trailers

Bearings - Secondhand Boat Trailer Buster!

It’s critical when buying a secondhand boat trailer that the bearings have been serviced by the current owner. The seller saying “the bearings will need servicing soon” is a red flag.

So is “I don’t know what kind of bearings they are” when you ask. If they’ve been serviced it is pretty likely they would know. At least, they should be able to check for you. Even by looking at an invoice from their mechanic.

In Australia, most boat trailer hubs are either Holden (HT or HQ) or Ford. Less common are Holden Torana, Mini Minor and Landcruiser. Different trailer manufacturers around the world tend to choose common local configurations.

The fact is some “Holden” wheel hubs use Ford bearings and vice-a-versa. Just to make life difficult some use a combination of both.

Knowing is essential knowledge.

A Holder HT hub won’t fit a Holden HQ rim. The same goes for Holden vs Ford hubs and rims. The stud patterns are completely different.

As it turned out when I bought my second boat trailer it used Holden HQ rims and Holden bearings.

The mechanic was able to service them fine. But wasn’t sure for certain if the rims were HQ. After a lot of Googling, I found out how to tell. Simply by measuring the distance between the centre of two-wheel studs (what the wheel nuts screw onto.)

Vital knowledge as I needed to buy a spare rim and tyre because the seller – and myself – had overlooked including one (I’m being generous.)

To save you the trouble I’ve included the table below to make it easier.

Finding The Wheel Stud Pattern On A Secondhand Boat Trailer

TypeNo. of studsStud diameter
Stud distance
HT Holden57/164 15/16 (4.9375)10863
HQ Holden57/164 3/4 (4.75)120.671
Ford Falcon51/24.5114.367

Source: Trailer Spares Direct

Buying a secondhand boat trailer means you’re probably going to want to tow it home. If the bearings are in bad shape you may not make it home.

Bad bearings are not usually quiet. They make a noise.

Secondhand Boat Trailer Bearing Checklist

  • Hook the trailer up to a car (your own or the sellers.) This stabilizes the trailer.
  • Then jack up one side until the wheel can be freely spun.
  • Spin the wheel. Taking care to keep your hands free from the trailer frame and mudguard.
  • It shouldn’t make any noise other than the sound of the wheel rotating on the axle.
  • Grinding or humming sounds tend to indicate a bearing problem.
  • So does wobble. Rock the wheel. If the wheel wobbles the bearings are useless.
  • Repeat for each wheel.
  • If the seller won’t let you do this -no sale! Walk away.

Here’s my experience.

My second boat, a 3.7 meter tinny (around 12 feet.) Looked pretty clean. Some dents in the aluminium. The motor seemed to be pretty good and only 3 years old. Only a little surface rust on the trailer that was wire brushable.

Boguns Gone Boating Secondhand Boat Trailer

For a secondhand boat trailer, there is going to be some rust. Light surface rust here or there is OK. Deeper and more widespread rust is a problem for newbies.

Also, beware of freshly painted, but clearly old and maybe rusty when buying secondhand boat trailers. Paint is sometimes used to cover up major structural rust. Even more so if they’ve used a paint such as “Hammercoat.”

All the components on the trailer were in as new condition. Winch, jockey wheel, lights etc.

The seller tells me “You’ll need to service the bearings soon.” Not really appreciating how to check I accepted this as friendly and wise advice to do ASAP.

I’m not saying he was trying it on. Rather, it’s possible he didn’t know. Which means the chances of the bearings being serviced are pretty slim.

I asked what make of bearing. He didn’t know. This alone should have ended the discussion with a firm no thank-you and walking away from the sale.


Because I was almost 100km from home and the route home was via two Freeways. The Princess and the Western Ring Road. Both very busy major routes.

Again, that’s not to say he was hiding anything. Rather, if you’ve had the job done regularly the brand is one of those things you’re going to remember.

Hindsight, as they say, is 20/20 vision!

But when it comes to buying a secondhand boat trailer you need all the knowledge you can get. Before you buy!

In my opinion, failing to maintain bearings is a strong indicator that other mechanical aspects of both the secondhand boat trailer – and the boat – are likely to be suspect.

The Wish I’d Checked The Bearings Secondhand Boat Trailer Waltz

Boguns Be Like, Fire? Yeah, She’s Cookin - Secondhand Boat Trailer

Paid for the boat and headed out for home. After getting onto the Princess Freeway at Geelong, to head back to Melbourne (99.6km or 61 miles to my suburb) I wound the window down. Only to hear an awful whirring sound coming from the trailer.

Got out to feel the temperature of the wheel hub (placing hand gingerly on bearing caps.) Warm. But not hot. I ended up stopping every 20 minutes or so to check. Same thing every time. Very warm, but not hot.

Made it home. A very stressful drive. I don’t recommend it. If I’d checked the bearings, as outlined above, I would never have bought the boat. Despite everything else being in pretty good shape overall.

If they had broken I would have been completely up the creek because it was New Years Eve.

At that time I did not have a roadside assistance cover that would have included the boat. Something I strongly recommend.

The bearings ended up being replaced before I took the boat out for the first time. It was only a few hundred dollars including labour. Worth every penny! A lot less if you are confident doing it yourself.

In my case, with chronic asthma, I paid a local boat service centre and was glad to do so.

There were a few other issues with the secondhand boat trailer I bought. Things you need to make sure you check.

I’ll get into some of those things below.

Tyres - Huh - Who Needs A Spare, Live Free, Man. Bah!!!

Buying a secondhand boat trailer in most Australian states means you don’t need a Roadworthy Certificate. So common sense safety checks are your responsibility.

The tyres are important. There should be plenty of tread, no worn rubber marks. They should be fully inflated.

A lot of boat trailer tyres are made for light trucks. This helps to ensure they are able to take the weight of the boat on the trailer.

As such they commonly take up to 40 PSI of air. While a lighter boat may sit better, when driving, with a little less inflation (I wouldn’t go less than 34 PSI personally) it’s a good idea to check the inflation.

Buying a secondhand boat trailer in most Australian states means you don’t need a Roadworthy Certificate. So common sense safety checks are your responsibility.

The tyres are important. There should be plenty of tread, no worn rubber marks. They should be fully inflated.

Secondhand Boat Trailer - Tyres & Rims

A simple pressure gauge is invaluable. Not just for when you are purchasing the boat and trailer. But when on the road too. For the times when you stop and check your trailer (a must-do procedure).

I bought a digital one from Aldi a few years ago. It seems to be accurate and has been invaluable.

During purchasing, poor inflation can indicate the possibility of a slow leak. Certainly not foolproof, however.

You’ll want to inflate a deflated tyre and check for leaks.

I bought a decent tyre pump from Repco some years back for about a hundred bucks. Always in my car. Better than stopping at a service station!

Rim size is a little less important, up to a point, on smaller, lighter boats. Bigger boats require more attention here. You have to balance the load capacity of the tyre with the height of the boat on the trailer, from the water, when you’re on the boat ramp launching.

Large rims with tyres can make launching and retrieving bigger boats more difficult. This is why larger boats often have twin axles with relatively smaller wheels. Two tyres on each side of the trailer.

This gets the boat into the water without needing to back down the ramp as far (deep.) Conversely, a larger wheel on a smaller boat helps keep your bearing out of the water. This can save on the life of your bearings.

Make sure the tyres clear the mudguards – also known as the “fender.” If it rubs easily you’re reducing your tyre life. It will stick you up somewhere. It could even lead to shredded tyres.

In the case of my second boat. The trailer came with 14-inch rims. With 185/R14 tyres. I replaced these with a lower profile 175/R14 tyre. The smallest profile I could get for the HQ wheel hubs. Lowering the height slightly and allowing more mudguard clearance.

For the record. The rims looked pretty awful. Old, flaky black paint and some minor, but ugly, rust. They were serviceable. But it was my intention to replace them with a set of nice Sunraysia white rims from Huntsman Products. A Melbourne dealer I chose because they offered a good deal. I bought the rim with the tyres on and fitted them to the trailer at home.

I’m not affiliated with the company – and receive nothing for mentioning them. But their service and products are excellent and I love supporting local Aussie businesses.

I honestly screwed up the order. I ordered the wrong tyre profile. Which would not have fitted under the trailer mudguards. They exchanged them for me. Even refunding the $30 difference. Very friendly and helpful folks.

Get A Spare Tyre With Your Secondhand Boat Trailer

Make sure you get a spare tyre with the secondhand boat trailer. Pretty easy to overlook.

How do I know? Because I forgot to check!

The second boat I bought and I was under pressure. Everything looked good. Had to get the wife back to Melbourne. It was New Years Eve. Almost 100km from home.

Boguns Be Like, Rope Ya Dope!

So, like a complete twit, I failed to check if the trailer had a spare wheel.

Just didn’t occur to me.

When you are buying a secondhand boat trailer, with or without the boat, the spare tyre is probably the number one thing you just might need – on the way home!

I was lucky in that I didn’t get a flat.

But, keep in mind. You’re going to have to know the rim size, tyre size and stud pattern if your trailer comes without a spare tyre. See the table I included above for how to check stud patterns.

Some secondhand boat trailers come with the spare tyre thrown into the boat. My first boat came that way.

That’s OK. As long as it fits and is a legal, serviceable rim and tyre.

Others come with the spare neatly attached to the trailer. Often on the frame. This is excellent. But not essential. You can always buy your own mount and DIY it later.

This is also one of the first things I did on the second trailer – after buying the spare.

Something I recommend as its easy to forget to “load the spare” into the boat. Or your car boot. Leaving the spare tyre at home just might ruin your day – or holiday!

Yeah. Not a lot of fun. While I hadn’t done that so far, I figured it was pretty much Murphy’s Law in play on this one. Buy and fit the mount!

While we’re still on the topic of secondhand boat trailer wheels. I recommend buying a good quality hydraulic jack if you don’t already have one. The scissor jacks that come with your car are awkward to use, if not dangerous.

I also carry a couple of small car stands in the boot. It just makes everything so much safer. Obviously these tools can sometimes be chosen to work with the tow vehicle too.

Finally, make sure you have a wheel brace that matches your trailers wheel nuts. The ones that come with cars are often single fit. Which probably isn’t going to help you on the side of the road if you get a flat tyre.

Ive yet to see a secondhand boat trailer that came with a jack, wheel brace or anything else, beyond the spare tyre.

Mudguards AKA “Fenders” On Your Boat Trailer

You need these by law in all Australian States (and probably most other sane places in the world!)

Boguns Be Like, She sure is a goer, I’d fix her meself except I have a football injury!

I’m embarrassed to say, in the excitement of buying my first boat, I overlooked these completely.

They were not “attached” and the reason was simple. If they had been attached they would have been horrific. They were so badly rusted as to be useless. Little doubt in my mind that the seller knew this.

I found them inside the boat in a box when I got home with some “extras” the seller had “thrown in” for me.

Too late to realise the mistake I’d made.

The way the trailer was set up they didn’t seem to be missing. Which is why they were easy to overlook.

No worries. Bought some new ones. Made a bracket to attach them to the boat trailer. The guards worked out fine. The secondhand boat trailer itself?

Well – that’s another story. See “Frame Rust” below….

Frame Rust On Secondhand Boat Trailers

On a secondhand boat trailer there’s “frame rust” and “frame rust.”

The first kind is superficial. It can be scrubbed off with a wire brush or even a sander if necessary. Then you can add rust killer, paint it up etc.

Then there’s the kind where the rust has eaten right through the frame. Leaving only a veneer of metal.

The metal with be flaky. Soft. Often like layers of honeycomb. Basically useless.

Don’t buy a secondhand boat trailer in this state. No matter how much you think you can fix it. Unless you can confidently weld or have a person who can weld in the family.

Because it’s going to get expensive – fast – to fix. In the case of my first boat – a new trailer.

Why did I replace the trailer?

Boguns Be Like, Just a few minor cosmetic repairs, mate! Secondhand boat trailer!

Because it broke.

On the highway. First trip out with the boat.

Leaving me with a boat heavily listing. Limping down the remaining 15km to the town we were planning on staying at.

Look. I’m a programmer. A tech geek. I had no idea what I was getting myself into.

I was lucky because:

  • It didn’t cause an accident
  • I was able to slowly drive to the town
  • No police officer saw us and gave us a much-deserved infringement
  • The holiday park we were staying at had a handyman who was able to effect a welded repair with some steel for $50.
  • The holiday park folks at Lake Nagambie Leisure Park were awesome about it all.
  • Nobody uploaded a video of me to Dashcams Australia on YouTube.
  • The guy who sold it to me knowing this… The less said the better.

The entire thing was that much harder because it was a fibreglass boat. Which weights four to five times more than an aluminium boat of the same size.

See the image above. If the rust is even a fifth as bad as you see in the photo – walk away.

In the case of my first secondhand boat trailer. Well, it’s pretty amazing what can be hidden with judicious use of paint if you’re determined to make a sale. So I discovered on the side of the Hume Highway just outside Seymour.

My – very – over-engineered mudguard brackets that I’d made, of all things, literally held the boat and trailer together as we limped into town. So my first introduction to Lake Nagambie Boat Ramp was a real ordeal. I had to get the boat off the trailer in order to have the trailer repaired. The mission was accomplished – but nerves were definitely on edge.

Are there exceptions to the rule?

The only one I can think of being where you are confident you can rebuild the trailer. Or will be replacing the trailer.

With smaller secondhand boats the value of the trailer is rarely taken into account by newbie buyers.

So a boat and trailer package secondhand will often start at the $1200 mark and upwards.

The fact is a new trailer for a small boat, 12 foot or less, is going to cost around $1200 upwards. So if the boats in good condition. The motor is in good condition. The trailer is probably the weakest link.

You’ll find the converse is also true. Great trailer, lousy boat or motor.

It’s going to cost you money. No matter what. A bad motor, in this price range, is often a better deal than a bad secondhand boat trailer. Providing the boat is OK.

Just make sure you understand the motor will be the first thing you replace, before you head out.

For a small boat, you can get a small motor (around 6hp) for under $1200 to get started. Another $1200 on top and you’ll get 10hp. You can pay less than this with a secondhand outboard motor - but buyer beware!

Tongue & Tow-ball Size On A Secondhand Boat Trailer

Not all tongues and balls are created equal.

I’m not talking about Mick Jagger or Gene Simmons here, either.

Boguns Be Like, Duct tape on the towball, man.  Genius! Secondhand boat trailer!

They do come in different sizes. A 50mm ball diameter is considered standard in Australia.

When buying my first secondhand boat trailer I learned an immediate lesson.

After happily paying for my first boat. Filling out the registration transfer papers. Basically feeling all warm and fuzzy.

Imagine my shock when…

The tow-ball size for the trailer tongue was to small for my standard 50mm two-bar ball!

The seller seemed pretty much sure 50mm isn’t standard. Even though it’s what he had on his car as well.

Fair dinkum! A real kick in the family jewels, that one.

OK. To be fair. Seller had a spare hitch. Which he did fit. With great difficulty.

To be fair . It then worked fine. However, if he’d not had one I’d have had to buy another the next day and return.

I could have changed the tow-ball. But then I’d have to change tow-balls every time I towed my box trailer. Plus – the guys who fitted my tow-bar had made darn sure my tow-ball wasn’t coming off.

Best to just make sure it fits your tow-ball.

Safety Chains - Because Your Trailer Should Stay Behind You, Not Ahead Of You

On a final note on the trailer towing setup. Make sure the boat trailer comes with safety chains to attach to your tow-bar. This is not optional.

If the tongue comes off the ball the chain is the only thing that’s going to keep your trailer from careening down the road.

On its own adventure.

Without you and your car.

Also, make sure there are shackles to attach the chain. Really easy to miss. While most service stations sell these, at a pinch, it’s best to come prepared. I always carry some spares that fit my tow-bar in the glovebox of my car.

Look, they’re easy to loose, yet are cheap to buy.

Did I learn this the hard way too? Yeah. How’d you guess?

First boat trailer didn’t come with shackles for the chain. Had to stop at a service station, on the side of the road, in peak hour, on a major suburban road.

Second boat trailer came with safety chains for the attaching the trailer to the car. But didn’t come with any chains at all to attach the boat to the trailer. Just the winch strap I tied it to the winch post using a rope (cringe!) that I had in the boot to get home.

Electrical – Lighting & Wiring On A Secondhand Boat Trailer

Stop lights, park lights and indicators need to work. It’s the law.

Trailer lights can be a real PITA. They are dunked in water, often saltwater, regularly. So the opportunity for failed globes, corroded wiring etc is higher than other kinds of trailers.

A Removable Trailer Light Bar Can Be An Effective Solution

My first secondhand boat trailer came with the kind on a batten that you remove before putting the boat in the water.

These are fine and legal. Providing they are in good working order. Just make sure they’re secured and can’t rise up while driving. Not only is the noise of their banging annoying. They can also chip or dent your boat if left hanging freely. They can also be obscured more easily as the force of driving tends to push them upwards.

Easy fix. A bungie cord does the trick.

My next secondhand boat trailer came with them attached to the trailer frame. This works great too. However, you need to make sure you wash them down after immersion. Especially in saltwater.

Make sure they work before you drive away after buying the trailer. If you’re not an electrician or experienced DIY type then they can be a major nuisance to fix. Beyond the simpler changing of the light globes.

Winch, Winch Strap, Safety Chain, Bow Stop & Jockey-wheel, Ratchet Tie Down

A secondhand boat trailer has obviously been “used.” Sometimes they have been used a lot. Sometimes even abused. More often simply neglected.

The winch is often left out in the elements. Even if the boat is covered. Make sure it’s not rusted. It needs to function freely when cranked. The ratchet gear should allow you to lock it so that it doesn’t reverse when you want it to keep the boat on the trailer.

On my first boat, I had to replace the winch strap. It was badly frayed. While this isn’t expensive to do it is certainly essential. Having it break while winching your boat on could leave you stuck at the boat ramp.

Having it break while towing, well, that’s going to be potentially very hazardous.

Same goes with the safety chain. My first boat trailer came with the safety chain. My next secondhand boat trailer did not.

Do not travel without the safety chain! The winch is not enough. They can – and do – fail. Allowing the boat to fall off the trailer. Onto the road.

In the case of my second boat. I tied it to the trailer, using the handle built into the bow to get it home. OK at a pinch. But not long term.

So before taking the boat out I bought a stainless steel chain (over-rated to one ton) and shackles to suit. Drilled holes into the winch post platform to attach the chain securely in place.

If the winch fails the boat is going to stay on the trailer!

This is the kind of crazy logic that mystifies me. The original owner raves about how he used the boat at Lake Mulwala. Ove 300km from his home. It seems that he drove up a major freeway and highway without chains. Dozens of times for years?

Yet. For less than $30 for stainless steel chain and shackles – plus ten minutes work – you’ve got the safety setup all done and legal.

You tell me. Which makes more sense?

Jockey Wheel

The other often abused, but necessary item when choosing a secondhand boat trailer is the jockey-wheel.

While not legally required your groin and stomach will thank you for not developing a hernia lifting the trailer onto the tow-bar!

Not to mention moving the trailer around the yard.

If there’s something that is usually easy to replace, relatively cheap and a DIY item it’s the jockey wheel. So while not immediately critical it’s something you need to consider.

Ratchet Tie-Down

Boat Trailer Ratchet Tide Down

I’ve left this to last. The ratchet tie-down is used to secure the back of the boat to the trailer. Unless the secondhand boat trailer you buy has newish ones – buy a new one.

I’ve found these to be a really unreliable piece of kit. Rusty ratchets on the tie-down will stick you up on the boat ramp. Like mine did. Rather than spring for the $30 or $40 new tie-downs I stupidly decided to make do on my first boat.

Don’t fail to replace them. It wouldn’t lock properly, then failed utterly.

False economy.

Spend the money. It’s worth it!

Brakes On A Secondhand Boat Trailer – If Applicable

None of my boats required brakes. They were below the weight where they become mandatory.

However, if they are fitted they need to have been serviced and be in good working order. On a trailer with brakes its likely the boat is going to be over one ton (that’s metric – over 1000kgs).

So faulty brakes on a secondhand boat trailer that needs them is a problem. This is a little more complex than checking bearings, rust etc on a secondhand boat trailer. So I recommend having them checked by a boat inspection service – or a family member if they are a mechanic.

Concluding Thoughts – Don’t Be In A Hurry!

There’s more to consider. I may have left something important off this list. If so let me know via the Contact page. However, it’s more information than I started with.

Just make sure you take your time. Try and enjoy the browsing as much as the buying. In other words don’t be in a hurry!

Taking your time. Looking for problems will save you money, time and possibly the life of others as well as your own.

Remember. There are shonky operators selling secondhand boat trailers. There are also well-meaning people who don’t know anything about the subject.

Boguns Be Like, Just A Few Waves, Man!

It’s your responsibility to make sure what you are buying is safe and serviceable.

In the budget range (below $3000) for a small boat (under 14 ft), trailer and motor you are usually going to find one of the three items aren’t equal to the others.

  • A good boat, poor motor and poor boat trailer.
  • A good boat, fair motor and poor boat trailer
  • A good boat trailer, fair motor and poor boat
  • A poor boat, good motor and a debatable boat trailer
  • A poor boat, poor motor and good boat trailer

There’s a whole lot in between. You may find you need to shop for each of the big three seperately.

For example – find a good secondhand boat. A good secondhand motor from another source (or a new one) and then a good boat trailer from yet another source (or a new one.)

It depends widely on where you live, how far you are willing to travel and what’s available in the marketplace at the time you’re looking.

Take your time!



August 2, 2021 at 6:50 pm

You are extremely unlikely (imposible) to get an interstate registered trailer registered in NSW

– Reply

Dave says:

August 3, 2021 at 1:55 pm

G’day Rod, Thanks for commenting. That’s interesting regarding NSW as I know in Victoria it’s pretty easy. I’ll look into why this is as I had no idea it was so hard there! Clearly safety is the concern.

Thanks Again!!