About Powertrain Unit Factory

Powertrain Unit Factory manufactures components vital to Honda's high performance, high quality automobiles, supplying Honda's factories domestically and globally. Its automated production line and strict quality control enables integrated production from materials to finished products.

Engine Components

Engine Valves

Engine Valves

Engine valves are used to rapidly induct air-fuel to compress and explode, and rapidly discharge combustion gas from the engine.



Converts piston rectilinear motion to rotary motion. Crankshafts demand precision, balance, and strength.

Con-rods (Connecting Rods)

Con-rods (Connecting Rods)

Conveys reciprocating energy from the pistons (spanning thousands of revolution per minute) to the crankshaft.

Transmission Components

Transmission Gears

Transmission Gears

Transforms engine revs to the drive system through selectable gears.

CVT Pulleys

CVT Pulleys

The most important component in CVT's (Continuously Variable Transmissions), consisting of two opposing pulleys.

4WD Components

Transfer Assemblies

Transfer Assemblies

For 4WD systems: Transmits motive power from the transversely positioned engine at the front perpendicularly to the propeller shaft, using high-precision hypoid gears.

Dual Pump System Assemblies

Dual Pump System Assemblies

Compact unit combining Honda's unique 4WD system with integrated dual pump system (allocating torque to the rear wheels depending on driving conditions), with the rear differential gears.

Differential Assemblies

Differential Assemblies

When a automobile turns, the distance travelled by the right and left tires differs. Differential assemblies allocate the engine's turning force according to the rotation speed of each tire, allowing the car to turn smoothly.

Suspension-related Components

CVJs (Constant Velocity Universal Joints)

CVJs (Constant Velocity Universal Joints)

Transmits without loss, torque from high-output engines to the wheels, featuring Honda's uniquely developed technologies.

Access Map

Honda Motor Co., Ltd.
Powertrain Unit Factory

19 Matsuyamacho, Mooka, Tochigi Pref. , Japan

About Kumamoto Factory Activities

Powertrain Unit Factory has evolved, flexibly accommodating changing times.

Brief History

The Branch Plant Era


Engine Valve Plant is established in Moka city, in accordance with Honda's first satellite plant concept. Began with a staff of 35, consisting of five associates from Wako Plant and locally-hired staff.

Plant at time of establishment

Plant at time of establishment

The Parallel Era


Component Plant and Valve Plant are established within the same industrial complex.


Production of Honda's uniquely developed Constant velocity universal joints began.

The Parallel Era

The Moka Plant Era


Components Plant absorbs Valve Plant as the Moka Plant.


Buggy engine production commences.


World's first fully-automated crank forging line.

The Parallel Era

Buggy 200
V6 crankshaft
5,000t press machine

The Independent Era


Aluminum wheel production commences in Japan and the US simultaneously.


Con-rod machine processing line begins operation.


Tochigi Plant dedicated to NSX production is established.

The Independent Era

Aluminum wheel
All-aluminum lightweight sports car "NSX"

The Tochigi Factory Era


Tochigi Factory is established, combining Moka, Takanezawa and Haga plants.


Haga Plant begins operation.


Japan's first mass-production of electric vehicles begins at Takanezawa Plant.


Haga Plant, First Site absorbed by Moka Plant.


Takanezawa Plant transferred to Suzuka Factory.

The Tochigi Factory Era

Haga Plant
Rear differential case
Electric vehicle

World-class 4500t Press Line

The 4,500t press line completed in March, 2005 is a world-class forging line culminating all of Honda's hot forging technologies.

World-class 4500t Press Line

High-speed Multi-production Line Capable of Producing Various Components

Single pressing machine capable of forging various components such as crankshafts, transmission gears and hypoid gears, at industry-leading cycle times.

Automated High-speed Setup

Setup for a 5,000t press that took 3 associates 40 minutes, was reduced to one associate taking 10 minutes for a 4,500t press, drastically improving productivity.

Environmentally-friendly Forging Line

By succeeding in the replacing of graphite as a parting agent for crankshaft forging with a reusable "white" parting agent, liquid waste was reduced to zero, realizing a clean facility.
Oxide scale scatter typical of hot forging is managed by a "Scale recovery device," a "tub" surrounding the press, collecting and channeling scale to a basement pit, which is then taken outside of the building by conveyor belt.

* Parting Agent: Liquid used in forging press to separate product from mold, acting as a lubricant and coolant.
* Oxide Scale: Thin membrane appearing on material surface when heated.

Factory List

Saitama Factory

Sayama Automobile Plant

Ogawa Plant

Yorii Automobile Plant

Suzuka Factory

Kumamoto Factory

Transmission Factory Outboard Engine Plant

Powertrain Unit Factory