Hitachi Washing Machine Gearbox, For Newer Twin Tub Models
The washing machine gearbox, which technicians call the transmission or gear case, is the mechanical unit that transfers the motor’s drive to the wash tub, converting fast rotation into the slow, powerful movement that drives the agitator.
Cool.sa supplies this gearbox for newer Hitachi twin tub machines. The body is reinforced plastic in a ribbed conical form, with a splined steel output shaft and a shaft seal.
Key Features
- Gearbox for newer Hitachi twin tub washing machines
- Reinforced plastic body in a ribbed conical form
- Lightweight and corrosion free
- Splined steel output shaft with shaft seal
- Mounting ears with bolt holes
- Internal gears transferring motor torque to the wash tub
Technical Specifications
| Specification | Value |
| Part type | Washing machine gearbox (transmission) |
| Compatibility | Newer Hitachi twin tub machines |
| Machine type | Twin tub, semi-automatic |
| Body material | Reinforced plastic |
| Shaft type | Splined steel with shaft seal |
How to choose? Match brand first, then generation, then measurements. If you are unsure, send us a photo of the old gearbox and we will identify the right one.
Why Washing Machine Gearboxes Fail
A gearbox is a mechanical part that wears with use, and four things accelerate it:
Overloading. A load beyond capacity multiplies the torque on the gears every cycle.
A loose belt. A slipping belt delivers repeated shock loads instead of smooth drive.
Water leaking past the shaft seal. This is the most important cause on plastic gearboxes specifically. Water reaching the gears destroys them quickly.
Running with too little water. Sharply increases friction against the load.
Replacement Guide
⚠️ Disconnect power and empty the machine of water before starting.
- Unplug the machine, close the water valve and empty the tub completely.
- Remove the agitator from the gearbox shaft.
- Lay the machine on its side on thick cloth to protect it from scratching.
- Photograph the gearbox position and belt before removal. Your only reference on reassembly.
- Remove the belt from the gearbox pulley and the motor pulley.
- Remove the gearbox mounting bolts from the tub base.
- Withdraw the gearbox.
- Compare new against old before fitting: body material first (plastic or metal), then shaft length, bolt centre distance and pulley diameter. Any difference means stop and contact us.
- Fit the new gearbox and tighten the bolts evenly. Do not overtighten, as a plastic body cracks under excess torque.
- Confirm the shaft seal is seated correctly.
- Refit the belt with correct tension: tight enough not to slip, not so tight that it strains the bearings.
- Fit the agitator and confirm it is secure on the shaft.
- Stand the machine upright and run a short cycle with no laundry, watching rotation and checking for leaks around the shaft.
Extending Gearbox Life
- Do not overload the machine. The single biggest factor in gearbox life.
- Inspect the shaft seal regularly. The most important maintenance point on a plastic gearbox.
- Check belt tension every six months.
- Do not overtighten the mounting bolts, as the plastic body cracks.
- Do not run the machine with too little water.
- Distribute laundry evenly in the tub before starting.
- Stop the machine immediately on any abnormal noise, and do not complete the cycle.
Common Applications
- Newer Hitachi twin tub machines in homes
- Labour accommodation and company housing, where machines run near-continuously
- Rest houses and farms, remote from service centres
- Small laundries and repair workshops
- Appliance repair workshops as working stock
Why Buy Your Washing Machine Gearbox From Cool.sa
- We stock both Hitachi generations, older and newer. Send a photo of your gearbox and we will identify the correct type.
- We confirm fitment by measurement before shipping, not by brand alone. Most sellers publish no measurements at all.
- Five brands from one source: Hitachi, Dansat, LG and Panasonic.
- Stock inside Saudi Arabia with fast delivery.
- VAT invoicing for corporate, business and labour accommodation procurement.
- Bulk pricing for laundries, labour accommodation and appliance repair companies.
- Full range of washing machine gearboxes across brands.
Frequently Asked Questions
Q1. What is the difference between the old and new Hitachi gearbox?
Body material and design. The older one is cast aluminium with a brake lever on the face; the newer is reinforced plastic in a conical form. They do not interchange. Open the access panel and look: silver metal means older, white plastic means newer.
Q2. Is a plastic gearbox weaker than a metal one?
Not necessarily. Reinforced plastic is lighter, corrosion free and transmits less vibration. But its weak point differs: water leaking past the shaft seal destroys the gears faster. Inspect the seal regularly.
Q3. Does it fit any Hitachi washing machine?
It fits newer twin tub models, but measurements are the final reference. Send us the shaft length, bolt centre distance and your machine model number.
Q4. The motor runs but the tub does not turn, has the gearbox failed?
Not necessarily. Check the belt first, as it is the most common cause and costs a fraction of a gearbox.
Q5. How do I know it is the gearbox and not the belt?
Disconnect power and turn the agitator by hand. If it spins completely freely with no resistance, the gearbox has lost drive. If it has normal resistance, check the belt and motor.
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