400 Commonwealth Drive, Warrendale, PA 15096-0001 U.S.A. Tel: (724) 776-4841 Fax: (724) 776-5760 SAE TECHNICAL PAPER SERIES 1999-01-3742 The New Allison HD4070 Transmission – Design, Development and Applications Timothy J. Cooney Allison Transmission Division, General Motors Corp. International Truck & Bus Meeting and Exposition Detroit, Michigan November 15-17, 1999Downloaded from SAE International by Univ of California Berkeley, Wednesday, August 01, 2018The appearance of this ISSN code at the bottom of this page indicates SAE’s consent that copies of the paper may be made for personal or internal use of specific clients. This consent is given on the condition,however, that the copier pay a $7.00 per article copy fee through the Copyright Clearance Center, Inc.Operations Center, 222 Rosewood Drive, Danvers, MA 01923 for copying beyond that permitted by Sec-tions 107 or 108 of the U.S. Copyright Law. This consent does not extend to other kinds of copying such ascopying for general distribution, for advertising or promotional purposes, for creating new collective works,or for resale. SAE routinely stocks printed papers for a period of three years following date of publication. Direct your orders to SAE Customer Sales and Satisfaction Department. Quantity reprint rates can be obtained from the Customer Sales and Satisfaction Department.To request permission to reprint a technical paper or permission to use copyrighted SAE publications in other works, contact the SAE Publications Group. No part of this publication may be reproduced in any form, in an electronic retrieval system or otherwise, without the prior wr itten permission of the publisher. ISSN 0148-7191 Copyright 1999 Society of Automotive Engineers, Inc. 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 paper if it is p ublished in SAE Transactions. For permission to publish this paper in full or in part, contact the SAE Publications Group. Persons wishing to submit papers to be considered for presentation or publication through SAE should send the manuscript or a 3 00 word abstract of a proposed manuscript to: Secretary, Engineering Meetings Board, SAE. Printed in USAAll SAE papers, standards, and selected books are abstracted and indexed in theGlobal Mobility DatabaseDownloaded from SAE International by Univ of California Berkeley, Wednesday, August 01, 20181 1999-01-3742 The New Allison HD4070 Transmission – Design, Development and Applications Timothy J. Cooney Allison Transmission Division, General Motors Corp. Copyright © 1999 Society of Automotive Engineers, Inc. ABSTRACT Allison Transmission has been a key player in the Military and Heavy Duty Commercial truck markets for manyyears. These tough vocations require transmissions thatare not only capable of heavy loads, rigorous duty cycles,and proven reliability, but also provide value for the end-user and maintain compatibility with leading edge techno-logical improvements of engines and other parts of thevehicle system. The Allison HD4070 transmission is oneof the latest transmission offerings from Allison Transmis-sion to meet the “next generation” heavy-duty vehicleneeds. This product increases value to the vehicle man-ufacturer and customer, and provides compatibility withthe fast changing electronics capabilities of modern vehi-cle systems and engines. These improvements areoffered in a durable design that has been the trademarkof Allison transmissions in these markets. This paper willdescribe the application, design, development and opera-tional principles of the HD4070 transmission for the mili-tary and commercial heavy duty markets. INTRODUCTION The roots of the Allison’s automatic transmission go backfifty years to the introduction of the first automatic trans-missions for the agricultural tractor market. From