The big question is, Can You Convert 2WD to 4WD and add 4×4 to a stock 2WD truck? I mean how hard can it be right? VERY HARD! and VERY EXPENSIVE! With that being said, it definitely can be done. This article discusses the modification process and what is involved when converting a 2WD to a 4WD.
You can 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 consideration.
Table of Contents
Convert 2WD to 4WD: SHOULD YOU DO IT?
We’ve established at this point that it is possible to add 4×4. So, the real question we should be asking is not really if it is possible, but rather if it is a financially feasible project. Meaning, it will be a cheaper alternative to sell your existing 2WD and purchase a used 4-Wheel Drive. Something to consider.
Okay, so to make our job a lot easier you will need a donor vehicle of the same model as the one we are converting from 2wd to 4wd. You could probably source at a junkyard for a lot cheaper than say purchasing a used one to add 4×4.
New 4WD vs Old 4WD
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. These electronic sensors and wiring loom will need to be connected to the ECU and other complicated electronic management systems. This means 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 some ready-made bolt-on 4WD kits for older pre-1990 model Fords and Chevys here.
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. So the modern 4WD will have features like traction control systems, wheel sensors, more electronic wiring, and sophisticated braking systems, and in the case of an
If you want to convert 2WD to 4WD on a modern truck, I want to emphasize how important it is to own a decent ODBII Scanner. Diagnosing issues on any modern, 4WD can be nearly impossible with all their sophisticated sensors and electronic components. If you do not already own one I would highly recommend this OBD2 Scanner & Engine Fault Code Reader on Amazon. It’s the #1 bestseller with almost 30,000 good reviews, so check it out! It will save you heaps of money in the long run and unnecessary time at the dealerships.
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.
For this project, it’s beneficial to choose manufacturers known for diverse vehicle platforms. They use shared chassis, drivetrains, and components across various models to reduce development costs. This strategy avoids the need for separate chassis or wiring changes for different models. It’s a positive aspect to consider for our ambitious 2WD to 4WD conversion project.
Once you have 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 items. Large manufacturers like Ford, Chevy, Toyota, and Volkswagen, for example, are renowned for doing this.
Certain aftermarket companies offer these fabricated packages or kits to allow you to do a DIY conversion, especially If it’s a very popular truck and the bolt-on conversion is simple enough.
So what are 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:
|A transfer case||Transfers power from the transmission to front and rear axles|
|Upgrade your transmission tail-shaft / output shaft||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|
Let’s next look at the transfer case since this is the core of the modification. You get this to function correctly and we are looking good.
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.
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.