SA E TECHNICAL PAPER SERIES Friction and Stick-Slip Durability Testing of ATF William C. Ward, Jr., James L. Sumiejski, Christian J. Castanien, Thomas A. Tagliamonte, and Elizabeth A. Schiferl The Lubrizol Corp. SAE The Engineering Society Fuels & Lubricants =For Advancing Mobility -land Sea Air and Space, Meeting & Exposition LIA~I~AIA I Baltimore, Maryland INTERhvnr rvrvn~ October 17-20,1994 400 Commonwealth Drive, Warrendale, PA 15096-0001 U.S.A. Tel: (41 2)776-4841 Fax:(412)776-5760 Downloaded from SAE International by Imperial College London, Sunday, September 23, 2018The appearance of the 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. Thisconsent is givenon thecondition, however, that the copier pay a$6.00 perarticle copy fee through the Copyright Clearance Center, Inc. Operations Center, 222 Rosewood Drive, Danvers, MA 01 923for copying beyond that permitted by Sections 107 or 108 of the U.S. Copyright Law. This consent does not extend to other kinds of copying such as copying 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 Service Department. To obtain quantity reprint rates, permission to reprint a technical paper or permission to use copyrighted SAE publications in other works, contact the SAE Publications Group at (41 2) 776-4841. G& MO6lLfTY DATABASE All SAE papers, standards, and selected books are abstracted and indexed in the Global Mobility Database. No part of this publication may by reproduced in any form, in an electronic retrieval system or otherwise, without the prior written permission of the publisher. ISSN 0148-71 91 Copyright 1994 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 published 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 300 word abstract of a proposed manuscript to: Secretary, Engineering Activity Board, SAE. Printed in USA 9c-1203cm Downloaded from SAE International by Imperial College London, Sunday, September 23, 2018Friction and Stick-Slip Durability Testing of ATF William C. Ward, Jr., James L. Sumiejski, Christian J. Castanien, Thomas A. Tagliamonte, and Elizabeth A. Schiferl The Lubrizol Corp. ABSTRACT Recent commercial specification revisions for automatic transmission fluids (ATFs) have focused upon more stringent friction requirements. More stringent friction durability characteristics are assessed using the SAE No. 2 tester. The commercial specifications do not include provisions to evaluate low speed friction characteristics, which have been shown to relate to torque converter shudder. This paper focuses upon effective use of the Falex 6 Multispecimen Tester to evaluate friction durability and to evaluate low speed friction characteristics in conjunction with low speed friction apparatus (LVFA) testing. Falex 6 testing agreed with torque fade observed in SAE No. 2 tests. Low speed stick- slip durability characteristics were effectively differentiated for a number of field ATFs. Falex 6 testing coupled with LVFA testing was shown to correlate with field experience and other test methods related to torque converter shudder. Finally, a Variable Speed Friction Tester (VSFT) was developed to improve test method continuity and improve test quality. INTRODUCTION The automatic transmiss