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 2003-01-0246 Fuel Economy and Performance Potential of a Five-Speed 4T60-E Starting Clutch Automatic Transmission Vehicle Chi-Kuan Kao, Anthony L. Smith and Patrick B. Usoro General Motors Corp. Reprinted From: Transmission & Driveline System s Symposium 2003 (SP-1760) 2003 SAE World Congress Detroit, Michigan March 3-6, 2003Downloaded from SAE International by University of Minnesota, Wednesday, August 01, 2018All 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: permissions@sae.orgFax: 724-772-4891Tel: 724-772-4028 For multiple print copies contact: SAE Customer ServiceTel: 877-606-7323 (inside USA and Canada)Tel: 724-776-4970 (outside USA)Fax: 724-776-1615Email: Customer Service@sae.org ISSN 0148-7191Copyright © 2003 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 the 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 publication by SAE should send themanuscript or a 300 word abstract of a proposed manuscript to: Secretary, Engineering Meetings Board, SAE. Printed in USADownloaded from SAE International by University of Minnesota, Wednesday, August 01, 2018ABSTRA CT A wet multi-plate clutch, designated as the “starting clutch”, and a two-speed simple planetary gearset are used to replace the torque converter in the 4T60-E automatic transmission in order to study the potential improvement of vehicle fuel economy without sacrificing 0 – 60 mph acceleration performance. The starting clutch and the two-speed simple planetary gearset are designed to fit in the torque converter compartment. This paper describes the modified five -speed 4T60-E starting clutch automatic transmission system and provides vehicle test results to demonstrate its fuel economy and 0 -60 mph performance potential. INTRODUCTION The use of a starting clutch in place of the torque converter in an automatic transmission for vehicle launch offers the pote ntial for significant fuel economy gain. A wet multi-plate starting clutch was designed to replace the torque converter in an experimental five -speed automatic transmission in a previous work [1]. In [1], we provided vehicle data to show that the starting clutch 5 -speed experimental automatic transmission provides a fuel economy improvement of 11.4% over the production 3T40 3-speed automatic transmission and 7.2% over a five - speed experimental automatic transmission with viscous converter clutch for the combined EPA cycles without sacrificing 0 - 60 mph acceleration performance, and the launch quality was comparable with that of a torque converter vehicle. In this work, we explore the integration of starting clutch technology into a production 4 -speed 4T60-E automatic transmission. This was accomplished by designing a starting clutch with a two-speed simple planetary gearset to fit inside the torque converter compartment of the 4T60- E transmission. This two-speed gearset provided extra torque multiplication to make up for the torque converter’s torque multiplication factor. The resulting system was a 6.5: 1 wide-ratio spread five -speed starting clutch automatic transmission. This transmission was installed in a Chevrolet’s Lumina LS Sedan with a 3.1L engine. We will describe the system and present vehicle test results in the following section