Thinking about towing something with your 4WD? In this post, we cover every single upgrade you might consider getting and the information you need to make an educated decision about whether its actually needed, or just marketing fluff.
4WD’s often make exceptional tow vehicles, but that isn’t to say they don’t need a couple of upgrades, some of which are likely to be a legal requirement, and others which might be necessary, but not always.
To start off with, the most important thing you can do is to check that your vehicle is actually suitable to tow the trailer that you want. This goes far beyond just looking at your towing capacity, and if that is all you are looking at you will likely have an illegal towing setup.
Fortunately we have the ultimate towing guide that steps you through the 7 items you need to investigate (very easily) and check that you are compliant with.
Upgrade options to your 4WD for towing
If the item that you are towing is wider than your vehicle, there’s a good chance you need to get mirrors that are larger, or towing mirrors so you can see what is going on behind your trailer. This is a legal requirement, and you can read more about towing mirrors here, but essentially if you can’t see what is going on behind your trailer (reverse cameras are not a legal alternative) then you probably need towing mirrors.
You can buy cheap towing mirrors for under $100, and then the top of the range units are about $800
If you are towing anything that isn’t a light weight box trailer, its seriously worth while getting yourself an OBD2 reader, and this is even more the case if you have an automatic vehicle. Keeping an eye on the automatic transmission temperatures is crucial, and is one of the easiest ways you can cause extensive, costly repairs to your 4WD early on in its life.
Even if you don’t have an automatic transmission, an OBD2 reader that can clear codes is hugely useful when something does go wrong with your vehicle. You can read the code, and translate it to a problem, and you, or your mechanic have a place to start looking. We’ve used our Ultra gauge a number of times to clear codes, and wouldn’t be without it.
You can buy a cheap Bluetooth OBD2 reader for about 15 dollars, and connect it to an app on your phone if you want a budget option, or you can get a scan gauge or ultra gauge if you want a permanently mounted screen showing you everything that is going on with the 4WD. We love the ultra gauge being permanently mounted, as it just does its thing and you never have to worry about it.
Automatic transmission cooler
The large majority of 4WD’s sold today come with automatic transmissions, and if you have one and don’t monitor the temperature, and don’t have a transmission cooler, you could be in a world of pain. We’ve written a comprehensive post about how to care for your automatic transmission, but if you are towing something that isn’t light weight, you really need to know your transmission is running happily.
An OBD2 reader will do this, and if its running hot (particularly in hilly conditions, or slow speeds) you need to get onto fitting an automatic transmission cooler. These are not expensive, and start off at about $200 for a reasonable generic kit, and a lot of people install them on their own. Alternatively, you can get dedicated kits for your specific vehicle with custom brackets for about $600, and it shouldn’t be more than a few hundred dollars to install one by a professional mechanic.
Our Dmax was constantly hitting 100 degrees towing our 1.5 tonne soft floor camper trailer; we’d have cooked the transmission towing our current Reconn R2 without a transmission cooler.
Even with a transmission cooler, we managed to hit 111 degrees in the Adelaide Hills towing our Reconn R2, and I have no doubt we’d have been in real trouble without it.
Transmission lockup kit or valve body upgrade
A further, common modification to automatic transmissions is to get a lockup kit or valve body upgrade. The first is a kit that will tell your transmission to lock up in different gears, and even to lock up earlier. Usually these are done with an ECU re-flash, but they can be piggyback units too.
A valve body upgrade is basically replacing components in the automatic transmission with upgraded items, and is often done when running higher power, or pushing the automatic box very hard.
If you want to go down this path, spend some time looking at the model specific options you have, as some lock up kits have a worse reputation than others!
Adjustable tow hitch
Your towing setup should be level when you are driving down the road. If the trailer points up or down, or your vehicle points up or down, you are not in a good place and you need to stop and re-evaluate. Sometimes this can be as simple as not having the right tow hitch, which forces the drawbar up or down.
An adjustable tow hitch will solve your issue, and they are not overly expensive, and can often be run in different orientations to allow you to get the perfect height. Every trailer and vehicle is a different height, and you need to get the two to marry in well.
If you are taking your trailer off road, consider the different tow hitch types, as a 50mm ball is less than ideal for real off road work.
Upgraded suspension or a GVM or GCM upgrade
One of the most obvious issues when you hook a heavy trailer up is the back of your 4WD sags. This is not only something that looks terrible, but its actually very bad for your vehicle handling and safety. When you apply a huge amount of tow ball weight, the rear of the vehicle goes down, which causes the front of the vehicle to go up.
Essentially, the leverage shifts some weight from the front of the vehicle to the rear. This is bad in many ways when extreme, but importantly it reduces your steering capacity and braking dramatically.
Sometimes a set of air bags is the perfect solution to raise the rear and re-distribute some weight onto the front. However, if you are constantly towing, or you always have some weight in the rear of your vehicle you are much better off replacing the springs with suitably rated units, and you may still have the option of air bags.
However, before you upgrade any suspension, get the entire vehicle and trailer weighed when you are at maximum weight, as you may find the problem goes beyond just suspension.
We did this on our Dmax many years ago, and found we were drastically running out of capacity, so had to get a GVM upgrade. This was using the same suspension we would have run anyway, but it also came with engineering re-rating the GVM of the vehicle.
Some GVM upgrades also re-rate the axles, allowing you to carry even more, and you can also get GCM upgrades in some states too, which allows you to weigh more overall (car and trailer).
There’s probably not too many vehicles that are sold today without reversing cameras, but if you haven’t got one and you regularly tow, you should seriously consider getting one. They are cheap, work amazingly and they make life so much easier.
I often hook our trailer up myself now, with just the reversing camera and a bit of guess work. It gives you confidence that everything is hooked up properly, and some people wire the reverse cameras up so you can flick to them while driving to check everything is all OK.