Hybrid Drive Unit & CVT Repair
Precision Care for the Intersection of Electricity and Motion
Unlike a traditional automatic transmission with clutches and bands, or a standard CVT that uses a belt and pulleys, most modern hybrids utilize a Hybrid Drive Unit (often called an e-CVT). This sophisticated component houses two high-voltage electric motors and a planetary gear set.
Because it lacks the “friction” parts of a normal gearbox, it is incredibly durable—but it is not maintenance-free.
Why Hybrid Drive Units Need Specialist Care
1. High-Voltage Dielectric Properties
The electric motors inside your drive unit are submerged in specialized transmission fluid. Over time, this fluid can break down and lose its “dielectric” properties. If the fluid becomes conductive, it can cause an internal short circuit, leading to a catastrophic (and extremely expensive) failure of the entire drive unit.
2. Heat & Breakdown
Hybrid motors generate significant heat during “Regen” and high-speed driving. This heat shears the fluid molecules, reducing the lubrication available for the planetary gears and bearings.
3. The “Lifetime Fluid” Myth
Many manufacturers claim these units have “Lifetime Fluid.” However, at our Hybrid Service Centre, we have seen that replacing this fluid every 80,000km to 100,000km significantly extends the life of the bearings and protects the internal motor windings.
Our Drive Unit & Gearbox Solutions
Hybrid-Specific Fluid Exchange
We don’t use “universal” transmission fluid. We use specific Low-Viscosity Dielectric Fluids (such as Toyota WS, Honda ATF-DW1, or specialized EV fluids) that are designed to be non-conductive and heat-resistant.
Inverter-Motor Signal Diagnostics
If your car is shuddering or making a “whining” noise, the problem might not be mechanical. We use high-speed oscilloscopes to check the electrical signals being sent from the Inverter to the Drive Unit motors to ensure the “phasing” is correct.
Bearing & Seal Replacement
If your drive unit has become noisy, we offer precision bearing replacement. Often, a “failed” transmission is simply a worn-out carrier bearing—repairing it is significantly cheaper than replacing the entire unit with a new one.
Traditional Gearbox Service
For our non-hybrid customers, we offer full service for:
Automatic Transmissions: Filter changes and fluid flushes.
Manual Gearboxes: Clutch replacement and gear synchronization repair.
DSG/Dual-Clutch Systems: Specialized calibration and fluid service.
Symptoms of Drive Unit Trouble
A high-pitched “whining” or “clunking” sound while accelerating.
The gasoline engine revving higher than usual without a corresponding increase in speed.
Vibration when the electric motor transitions to the gas engine.
Metal shavings found during a routine fluid inspection.
“The e-CVT is the engineering marvel of the hybrid world. While it has fewer moving parts than a standard transmission, the fluid acts as both a lubricant and an electrical insulator. Regular fluid analysis is the cheapest insurance policy you can buy for your hybrid.”