Service Training for Volkswagen Dual Clutch Gearbox 0DD

Quick guide from the manual

This document is a Self-study Programme (SSP 538) designed for service training on the Volkswagen 0DD dual clutch gearbox. It provides technical details on the design, function, and service procedures for this specific gearbox, which is primarily used in hybrid vehicles like the Golf GTE. It is not a replacement for official service literature; always refer to ELSA for current testing, adjustment, and repair instructions.

Overview of the 0DD gearbox

The 0DD gearbox is a compact dual clutch transmission developed for hybrid vehicles, suitable for A0- and B-segment cars. It consists of three main assemblies:

• Hybrid module: Contains the electric drive motor, cooling jacket, and clutch pack.
• Manual gearbox: Includes the gear train, shafts, and differential.
• Mechatronic unit: Controls the gearbox functions, including oil pressure and gear selection.

Hybrid module design

The hybrid module integrates the electric drive motor (V141) and a clutch pack. The clutch pack consists of three wet clutches:

• Disengagement clutch K0: Connects or separates the combustion engine from the electric drive motor.
• Drive clutches K1 and K2: Transmit torque to the respective gear train halves.

The disengagement clutch K0 is disengaged when driving exclusively with the electric motor and engaged when the combustion engine is driving or when both power units are used (boost mode).

Manual gearbox components

The manual gearbox section details the mechanical transmission of power:

• Input shafts: Two concentric shafts rotating independently.
• Output shafts: Two shafts that engage with the final drive gear of the differential.
• Selector shafts: Four shafts moved hydraulically to select gears.
• Synchromesh: Uses carbon-coated synchro-rings to withstand high mechanical and thermal loads.

Mechatronic unit and oil circuits

The mechatronic unit is immersed in gear oil and separated from the gear case by a partition. It contains:

• Hydraulic pump motor (V401): A brushless DC motor that drives two gear pumps.
• Valves: Proportional solenoid valves activated by PWM signals to regulate oil flow.
• Sensors and Actuators: Numerous sensors monitor gear selection and pressure, while actuators control the gear shifts and clutch engagement.

There are two distinct oil circuits:

• High-pressure oil circuit: Operates at 43–53 bar, supplied from the mechatronic unit oil sump.
• Low-pressure oil circuit: Regulated to 1.5 bar, supplied from the gear case oil sump, used for lubrication and cooling.

Service and maintenance procedures

The manual outlines specific service requirements:

• Basic setting: Performed using a vehicle diagnostic tester in five steps, including oil pressure buildup, synchronization of gears, and adaptation of clutch bite points. A road test is required afterward.
• Oil change: Requires a vehicle diagnostic tester to activate solenoid valve N93 to drain the high-pressure circuit. The double gear pump must be run to circulate oil during the level check to ensure correct levels in the gear case and mechatronic unit.