At the beginning we all wonder what are the differences between Gearbox V2 and V3 and I think that sooner or later most Airsoft players will come into contact with both versions, because after all, a good collection of replicas never hurts!

In this article I show you what are the main differences between the V2 and V3 Gearboxes, but if you want to know how a gearbox works inside a replica, I suggest you also read this article.

The evolution of the Gearboxes

Before starting with the description of the differences between the V1 and V2 models, let’s do a brief recap on the invention of gearboxes which will be useful for you to understand the nomenclature and where the various versions come from.

Like most of the technologies used in the construction of the replicas, too the first gearboxes come from the Tokyo Marui companywho we can consider to have been the pioneers in the construction of AEG replicas and who developed what is known as the V1 gearbox.

The first gearbox was used in a replica of the French FAMAS. For the company, this replica was the first to use the V1 gearbox which was developed especially for this model.

The next project saw the making of the V2 gearbox which was used on the AR platform replicas and when it came time to make further replica models, the V3 gearbox appeared.

Over time, most manufacturers began to copy these solutions and with them the nomenclature.

It is worth mentioning that in addition to these models, there are also other gearbox versions such as, for example, the V7 used for the m14 replicas.

Apart from the versions discussed in this article, the others are less used and when we come across a gearbox that does not fall into V2 or V3, we often say directly that it is an “MP7 gearbox” or “SR-25 gearbox” , indicating the replica model as an indicator for the gearbox version.

What are the differences between Gearbox V2 and V3?

After this introduction, we can move on to explaining the fundamental differences between the two versions. One may be tempted to say that there are very few, because after all, many parts can be used for both.

As often happens, even here the matter becomes more complicated as the subject is deepened. First of all, the gearbox versions discussed are used in completely different replicas.

The V2 gearbox is most often used in AR platform replicas, but we can also find them in replicas that mimic the SCAR system. However, there may be exceptions, so I always recommend checking before buying.

So we can say that their main difference lies in the shape which varies according to the replica model where it is used.

Another important difference concerns the position of the engine and cable wiring. In general, we can say that the engine, depending on the version of the gearbox, can be both an internal and an external part.

Gearbox V3 for AK-47
Gearbox V3 for AK-47

Here the motor is mounted in a basket screwed to the rest of the gearbox. This is a good solution that facilitates stability when mounting the engine.

In these versions they are often used engines in the short variant and allows you to test the functioning of the components without problems, even if it is not installed in the replica.

In the V2 it is also possible, but not so convenient. Here the engine, which is usually in the long version, is a completely separate element from the rest of the gearbox and is placed in the handle of the replica.

The difference is also in the routing of the cables inside the replica.

In a replica with gerabox V3 and with a normal trigger without a MOSFET, it is also possible replace the cables without opening the gearbox because these are welded to the contacts from below, so they go around the shell and are separated from the motor and battery connection.

In the gearbox V2 it is a little more difficult because both the solder points on the trigger assembly and most wires require the shell to be opened. In addition, the wiring harness passes under the engine axle, where it is often exposed to damage from elements that operate the replica.

On the other hand, however, we can choose whether to bring the cables forward or backwards. For someone who has been practicing Airsoft for some time, this will probably already be obvious, but I say this to be clear.

Due to the differences already described, and due to the different construction of the shells themselves, both versions described also have different trigger groups.

The last differences concern the smallest parts, which in most cases are still different between V2 and V3.

Quite often, the spring and guides are both different and in the era of replicas with QSC (Quick Spring Change) systems, you often have to look up this system in a particular manufacturer’s standards to be sure it fits. For both older and more traditional replicas, this is an important aspect to consider.

Even the cylinder heads and the nozzle are generally different. Here, however, a lot depends on the hop-up used and the specific component variants that are within the same gearbox version.

A good way to start looking for the right parts for our replica is to measure the factory ones and look for equal sized equivalents.

The last major component that is different is the selector plate. Usually those in V3 gearboxes are longer. Furthermore, there are also other places where the springs are attached.

What components do Gearboxes V2 and V3 have in common?

When I started with Airsoft, the versions described seemed like two different worlds to me. However, over time, as I’ve gained some experience, I’ve discovered that they have a lot in common after all.

First of all, here the standards for the gears are the same. We have three gears for each system that we can move freely between V2 and V3. Of course, without mixing sets with different ratios.

Furthermore, even the bearings are the same for both versions. If we have holes in two gearboxes, for example 8mm, we can use the same bushings interchangeably. The gear thicknesses are also universal.

Speaking of tuning, it is impossible to leave out the air group of our replicas, because after all, it is what guarantees the best possible performance. The good news for us is that both V2 and V3 gearboxes accept the same pistons with heads and cylinders.

So if we have our favorite set, we can use it without worrying about compatibility.


At this point you may be wondering “so is it better to choose a replica with v2 or v3 gearbox? “

As we have seen, there are some parts that we can use interchangeably. However, it is difficult to point to a gearbox that is objectively better.

My advice is to tell you “choose the replica model that you like best and that you can afford”.

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