The Japanese Kei Trucks are available in the market as either 2-wheel or 4-wheel drive. The 4-wheel version is better in terms of performance than the 2-wheel version. It can tackle any terrain. The 4-wheel version is slightly expensive. It is possible converting a 2-wheel to 4-wheel drive. You will only need to buy the 4WD shifter, front driveshaft, front axle, and springs. You will have to change the transmission of your mini truck. There are no differences between the manual or automatic transmission of 2WD and 4WD. Changing the transmission alone does not guarantee that the mini truck will be 4WD. You must change parts such as the steering box and the master cylinder.

Converting 2-Wheel to 4-Wheel Transmission

The 2WD and 4WD transmissions have very many similarities. The difference between the units is that the shaft of the two-wheel is long compared to the four-wheel, and there is a transfer case where the four wheels are connected. 

The Transfer Case

Some 2-wheel drive vehicles have a dummy transfer case. What do I mean by this? The dummy transfer case allows you to transform the transmission of such vehicles to four-wheel drive. In 4-wheel drive mini trucks, you will have the transfer case connected at the rear end of the gearbox. The transfer case plays the role of distributing the torque from the engine to the front and rear axles. It also plays the role of bringing uniformity between the RPM of the front and the rear wheels. The transfer case has sets of low-range gears for highway application.

You will need a transfer case to convert the rear wheel to a four-wheel. The transfer case brings the difference between the four-wheel drive mini truck and the two-wheel drive. It will asymmetrically distribute the torque and transfer most of it to the back axel. It is at this part that the core modification will happen. If it is correctly done, well and good, but if it is poorly done, your mini truck will give you more headaches.

Adding the 4WD Transfer Box to a 2WD

The backbone and main functionality in the 4WD is the Transfer box. If you fix this correctly, you will enjoy your new four-wheel transmission system. When adding the four-wheel transfer box, ensure it fixes well to the two-wheel transmission box. Since this process is tiresome and will give you too much headache, consider getting the entire transmission from a donor. The transfer case connects the front and the rear driveshafts to the rear and the front axles. When fixing it, make sure it is balanced. 

You Have to Upgrade the 2WD Suspension.

The four-wheel drive transmission is slightly heavier compared to the two-wheel drive transmission. You must install a new suspension that can carry your mini truck’s heavy four-wheel drive transmission.

Conclusion

Converting a mini truck from 2-wheel drive to 4-wheel drive is not complex, but it is essential to do this with a skilled mechanic.