400 Commonwealth Drive, Warrendale, PA 15096-0001 U.S.A. Tel: (724) 776-4841 Fax: (724) 776-5760 Web: www.sae.org SAE TECHNICAL PAPER SERIES 2006-01-0846 General Motors New Hydra-Matic RWD Six-Speed Automatic Transmission Family Jeff Baran, James Hendrickson and Michael Solt General Motors Powertrain Reprinted From: Tran smission and Driveline 2006 (SP-2001) 2006 SAE World Congress Detroit, Michigan April 3-6, 2006 The Engineering Meetings Board has approved this paper for publication. It has successfully completed SAE's peer review process under th e supervision of the session organi zer. This process requires a minimum of three (3) reviews by industry experts. All rights reserved. No part of this publication may be reproduced, stored in a retrieval system, or transmitted, in any form or by any means, electronic, mechanical, photocopying, recording, or otherwise, without the prior written permission of SAE. For permission and licensing requests contact:SAE Permissions 400 Commonwealth DriveWarrendale, PA 15096-0001-USAEmail: [email protected]: 724-772-4028 Fax: 724-776-3036 For multiple print copies contact: SAE Customer Service Tel: 877-606-7323 (inside USA and Canada)Tel: 724-776-4970 (outside USA)Fax: 724-776-0790Email: [email protected] ISSN 0148-7191 Copyright © 2006 SAE International Positions and opinions advanced in this paper are those of the author(s ) and not necessarily those of SAE. The author is solely responsible for the content of th e paper. A process is available by which discussions will be printed with the pap er if it is publishe d in SAE Transactions. Persons wishing to submit papers to be considered for presentation or publicat ion by SAE should send the manuscript or a 300 word abstract to Se cretary, Engineering Meetings Board, SAE. Printed in USA ABSTRACT The Hydra-Matic 6L80 is General Motors first model of a new, four-variant, rear wheel drive (RWD) six speed automatic transmission family. The four variants are the 6L45, 6L50, 6L80 and 6L90. The new, high performance 6L80 will debut in 2006 model year performance vehicles, including the Chevrolet Corvette C6 and new Cadillac STS-V and XLR-V. By 2007, GM expects to use the RWD six speed family in as many as 25 different car, truck and SUV models in RWD, 4WD and all-wheel drive configurations. While the Hydra-Matic RWD six-speed family was designed with four variants, the built in modularity requires only two different basic diameters of parts and “flexing” on part width (length) depending on specific torque requirements. This built in modular design enables a tremendous amount of part sharing and part scaling. Modularity minimizes engineering resources, improves investment and piece cost, speed to market and allows for a wide bandwidth of vehicle and engine applications. The current bandwidth of applications ranges from 2.5 L to 6.6 L engines. The planned engine torque capacity for the family ranges from 258 lb.-ft. to 520 lb.-ft. (350 Nm to 705 Nm) with flexibility for future growth. The RWD six speed family is expected to improve both fuel economy and acceleration performance. As an example, the 6L80 is expect ed to improve fuel economy by as much as four percent, while improving 0-60 mph times by as much as seven percent when compared to the current four speed automatic that it replaces. This was accomplished by a wider overall ratio spread of 6.04:1 compared to the typi cal 4.0:1 for conventional four-speeds. INTRODUCTION The motivation for undertaking a new six speed automatic transmission was to improve vehicle efficiency, performance and overall customer driving experience. The motivation for designing, developing, and building a six speed automatic transmission family (modularization) was for improved resource efficiency, both human and financial. The two small diameter variants, the 6L45 and 6L50, have the same basic part diameters and flex on the width (length) of va rious pa