Can You Convert 2WD to 4WD? The Surprising Answer Will Shock You!
Yes, it is possible to add 4WD to a 2WD truck, especially if the model has a 4WD version. Existing wiring, mounts, and brackets might align, but aspects like drivetrain, suspension, transmission, electronics, engine power, and differentials need careful consideration.
After owning a variety of 4x4s with over 20+ years of offroad and overlanding experience I can assure you that this 2WD to 4WD modification is a mammoth project. After doing a ton of research I will reveal my findings and explain the modification process and what is involved when converting a 2WD to a 4WD.
I do think that If you have access to a donor truck you’ll have all the miscellaneous parts that this job would require to add 4×4, so it becomes a simple stripping and fitting process for smaller components.
Below i listed some of the components you’ll need to convert 2WD to 4WD?
Let’s have a look.
You will require the below but not limited to the following:
| Component | Description |
|---|---|
| A transfer case | Transfers power from the transmission to front and rear axles |
| Front and rear driveshafts | Enhances transmission for 4WD compatibility |
| Front and rear drive-shafts | Required for 4WD; only front shaft for rear-wheel drive 2WD |
| Complete Front axle assembly | Front and rear driveshafts |
| Transfer case gear shifter | Controls engagement and operation of the transfer case |
| Wiring harness | Necessary if existing wiring lacks connections for 4WD |
| Upgrade / new 4×4 compatible transmission | Transmission modified or replaced to support 4WD functionality |
| Upgraded suspension | Modified to support added weight and components for 4WD |
| AND MORE… | Additional components and adjustments may be needed for 4WD conversion |
Before you proceed, let’s first determine if this is a viable project to undertake and what kind of expertise, engineering skills, and budget are required.
Convert 2WD to 4WD: SHOULD YOU DO IT?
We’ve established at this point that it is possible to add 4×4 to a 4×2 truck. So, the real question we should be asking is not if it is possible, cause anything is possible, but rather if it is a financially viable project. Meaning, will it be a cheaper alternative compared to selling your existing 2WD and purchasing a used 4-Wheel Drive?
The reality is that a 2WD and 4WD truck is designed and built very differently. Sure, if you compare a 2WD and 4WD of the same model and make, certain small components will fit, however, the main 4WD system, drivetrain, wiring looms, mounting brackets, support brackets, axles, u-joints, and electronics will be vastly different and will require quite a bit of engineering and some fabricating genius to make it all work since not all the components will fit together perfectly. The list of components requiring modifications is long!
Then there’s the issue of licensing…
Will You Convince the State Licensing Bureau?
If you manage to successfully pull off this conversion, remember, when you eventually decide to sell your truck, the title will still indicate it as a 2-wheel drive. Your other challenge will be convincing your State Licensing Bureau that it is now a 4WD. Even if you present the vehicle to them, chances are they won’t be easily swayed.
Expect a response like, “The original equipment manufacturer (OEM) has specified it as a 2WD, and their submitted documents support that classification.”
So, is this a project I would recommend? In short, with all the added complications, NO, I personally would not recommend it!
Okay, but let’s entertain this idea for a second and see what exactly needs to be done to convert your 2WD truck to a 4WD.
Selecting the correct Year model
Selecting the correct year model to add 4×4 will mean the difference between a relatively electronic-free, purely mechanical build versus a more modern 4WD with electronic sensors and wiring harnesses.
- Electronic sensors and wiring looms will need to be connected to the ECU and other complicated electronic management systems.
- If you’re not experienced in the auto-electrical field, you are going to need to call on the services of a very experienced auto-electrician.
There are, however, ready-made bolt-on 4WD kits for older pre-1990 model Fords and Chevys.
The older trucks have fewer electronics but, will require a bit of metal fabrication and some reinforcement to accommodate the leaf spring and solid axle conversion.
Modern vs Old 4WD
More modern 4WD trucks are a lot more sophisticated and complex in design, making the 2WD to 4WD conversion a lot more complex. This is because manufacturers are constantly under pressure to develop more user-friendly, greener, and safer vehicles.
- Modern 4WDs have features like traction control systems, wheel sensors, more electronic wiring, and sophisticated braking systems.
ADD 4×4 – IFS vs SFA
IFS (Independent Front suspension) more complex suspension component. So once you manage to get the mechanical side sorted out, you now are faced with the electronic nightmare. You will need lots of customization to add 4×4 and get the 4WD to actually function properly. It’s going to be a much easier and cheaper task to stick with a solid front axle setup with leaf packs, instead of the IFS with dampers and springs, lower control arms, stabilizer arms, linkages, ball joints, and the works.
Adding a 4WD Transfer box to a 2WD
The transfer case is the heart and soul of the 4WD and once you get this married up and functioning properly, you’ll be in a good position. What is entailed?
You’ll need to be able to marry the transfer case up with the existing transmission. Here you are better off purchasing or swapping the entire transmission with the transfer case from a donor 4WD truck since the hassle of opening the transmission to modify the box to accommodate the TC will be a headache. Click here to read about converting a 2WD transmission to a 4WD.
The transfer case will need to connect the front and rear driveshafts to the front and rear axles. The drive shafts will need to be balanced properly.
Converting a 2WD to 4WD Drivetrain
If the truck you are converting from 2wd to 4wd was originally available from the factory in that configuration, then a few trips to the auto salvage yard or a donor would give you the major and miscellaneous parts needed to pull it off.
On the contrary, if the truck you want to butcher was never offered in 4WD configuration, you have a major design and construction project to embark on. The expense, time, and expertise to accomplish this will be huge.
Upgrading the 2WD Suspension to handle 4WD
Due to the additional weight when you add 4×4 components, the 2WD suspension will require a substantial upgrade. Here we are talking about front and rear dampers as well as leaf packs. This alone will be a few thousand out of your pocket. The suspension upgrade is necessary to accommodate the additional weight from the transfer case, driveshafts, and differentials that have been added.
This excludes the other miscellaneous components that will all add extra weight. By converting the vehicle from 2WD to 4WD the weight will increase hence the stress on the chassis and all parts of the car. So you also have to modify the load-bearing capacity of the other parts of the vehicle to bear the stress.
Adding a 4WD Differentials
Opting to go with a solid front axle will be the easiest option here since it negates the need for all the extra components found on an IFS suspension. The front differential will need to marry up with the front driveshaft that connects to the transfer case. Once 4WD is engaged the transfer case engages the front driveshaft to power the front wheels. If the 2WD truck is rear-wheel drive with a rear axle, that eliminates the need for a rear axle.
2WD vs 4WD Engine Power
When you add 4×4 the transfer case, diffs, and other parts increase weight, impacting fuel efficiency and engine performance. 4WD drivetrains have more components, adding weight and slightly reducing engine power. To counter this, enhancing engine power is necessary. Begin with aftermarket exhaust, filters, and intake mods, then consider piston modifications later.
2WD to 4WD Convertion Cost
I would suggest you do the math first before embarking on such an elaborate project since the numbers will suggest it’s not a financially feasible option. You will need to purchase a donor truck or make multiple trips to the junkyard for components. The time, effort, and money wasted there alone will indicate it’s not a good idea.
Also, depending on the make, model, and sophistication level in terms of electronics will drastically increase costs. You are probably looking at a starting figure of around $3,500 as a starting point. This project could easily run close to the double figures into the thousands if you are going to do it properly.
Click Here For a FREE Basic Cost Breakdown to Convert 2WD to 4WD
Final Thoughts
In theory, if the 4WD truck was an older pre-1995 model and 4-wheel drive was a factory option for that model, you have a donor truck so that you have all the miscellaneous parts that this job would require, plus the fabrication skills needed, plenty of time, and a wad of cash you could do it, yes.
