Service Training

Self Study Program 850103

The 8-Speed Automatic Transmission 0C8 Design and Function

Volkswagen Group of America, Inc. Volkswagen Academy Printed in U.S.A. Printed 08/2010

Course Number 850103

©2010 Volkswagen Group of America, Inc.

All rights reserved. All information contained in this manual is based on the latest information available at the time of printing and is subject to the copyright and other intellectual property rights of Volkswagen Group of America, Inc., its affi liated companies and its licensors. All rights are reserved to make changes at any time without notice. No part of this document may be reproduced, stored in a retrieval system, or transmitted in any form or by any means, electronic, mechanical, photocopying, recording or otherwise, nor may these materials be modifi ed or reposted to other sites without the prior expressed written permission of the publisher.

All requests for permission to copy and redistribute information should be referred to Volkswagen Group of America, Inc.

Always check Technical Bulletins and the latest electronic repair information for information that may supersede any information included in this booklet.

Trademarks: All brand names and product names used in this manual are trade names, service marks, trademarks, or registered trademarks; and are the property of their respective owners.

Contents

Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1
Transmission Design . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3
Transmission Function . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17
Transmission Management System . . . . . . . . . . . . . . . . . . . . . . . . . . . 28
Electrical Components . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 34
Functional Diagram . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 38
Knowledge Assessment . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 41

Note Important!

This Self-Study Program provides information This information will not be updated. regarding the design and function of new For maintenance and repair procedures, models. always refer to the latest electronic This Self-Study Program is not a Repair Manual. service information.

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Introduction

The 0C8 8-speed automatic transmission is based on the previous 09D automatic transmission. This transmission uses the same basic components and has added two more forward speeds, helping both performance and fuel consumption.

All 2011 Touareg vehicles will have the 0C8 8-speed automatic transmission.

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1

Introduction

Technical Data

Developer/ Manufacturer	AISIN AW CO. LTD Japan
Designation	• Automatic transmission 0C8
Transmission Features	• Electrohydraulically controlled 8-speed planetary transmission with a simple primary planetary gear set and a Ravigneaux planetary gear set • Torque converter with slip-controlled torque converter lock-up clutch • Designed for longitudinal installation in combination with a transfer case
Control System	• Hydraulic control unit (valve body) in the oil sump with external electronic control module • Dynamic Shift Program DSP with separate sports program in "position S" and "Tiptronic" mode for manual gear changes • Special feature: Starting off in 2nd gear is possible in Tiptronic mode
Torque	Depending on version, up to 737 lb/ft (1000 Nm)
Service	For fl uid maintenance and intervals, see ElsaWeb
Weight	Depending on adaptation of the transmission to the engine, between 200 and 240 lb (91 and 108 kg)
Speed	Depending on engine, the top speed can be achieved in 6th, 7th or 8th gear

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Transmission Design

The 8-speed automatic transmission consists of :

• The torque converter with lock-up clutch

• The ATF pump

• The valve body

• The Lepellitier planetary transmission confi guration

• The transmission housing

• Auxiliary hydraulic pump for transmission oil

• ATF preheater

Planetary
Torque Converter
Transmission
ATF Pump
ATF Pre-heater
Housing
Transmission Fluid Auxiliary Hydraulic Pump 1 V475
Valve Body

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3

Transmission Design

The Torque Converter

Pump Wheel
Tuurbine Wheel
Stator
Torsional Damper
Torque
Converter Lock-
up Clutch
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Transfer Case
Engine
8-Speed Automatic Transmission
Electric Motor/Generator

The hydro-mechanical torque converter is a fl uid clutch. It is used both to transfer and multiply torque from the engine. It consists of a turbine, pump, stator and lock-up clutch.

Torsional dampers are installed in all torque converters. This allows the engine’s torsional vibrations to be minimized.

In hybrid vehicles with combined electric motor and combustion engine, the combustion engine drives the torque converter via a shaft. This shaft runs through the middle of electric motor (electric motor/ generator). If the electric motor is used to drive the hybrid vehicle, the torque converter is driven directly by the electric motor.

Different torque converters will be used depending on the engine and drive characteristics.

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4

Transmission Design

The Connection between the Engine to the Torque Converter

The torque converter is connected to the different engines via three lugs. Depending on the engine, 3 or 6 bolts are required to connect the lugs to the engine.

3.6L V6 FSI Engine

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3.0L V6 TDI

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3.0L V6 FSI

The Torque Converter Lock-up Clutch

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The torque converter lock-up clutch is a hydraulic multi-plate clutch. It locks the torque converter’s pump and turbine to eliminate slip.

Torque Converter Lockup Clutch

Depending on the vehicle operating status, this can be carried out at any time at engine speeds of over 1000 rpm.

Torque Converter

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5

Transmission Design

The Oil Supply

Depending on drivetrain, the 8-speed automatic transmission is equipped with the following oil pressure pumps:

• Combustion Engine: The ATF pump inside of the transmission

• Hybrid Drivetrain: The ATF pump inside of the transmission and the Transmission Fluid Auxiliary Hydraulic Pump 1 V475

Converter Housing with Converter Hub

ATF Pump

Oil Supply to the Valve Body

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The ATF Pump

In vehicles with combustion engine, the mechanical ATF pump (Automatic Transmission Fluid) is responsible for supplying the transmission with oil. It draws the ATF out of the oil pan, builds up the oil pressure and supplies the valve body with the hydraulic oil required for changing gears.

The oil pump is a crescent pump (duocentric oil pump). It is driven directly by the engine via the converter housing and the converter hub. When driven, the ATF pump’s pinion drive plates engage in two grooves on the converter hub.

In hybrid vehicles, this pump is driven by either the combustion engine and/or the electric motor/ generator.

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