INTERNATIONAL^ 400 COMMONWEALTH DRIVE, WARRENDALE, PA 15096-0001 USA. A Study of Additive Effects on ATF Frictional Properties Using New Test Methods Takanori Nakada, Takao Nomura Tatsuo Yoshioka and Minoru Nonoyama Toyota Motor Corp. International Fuels and Lubricants Meeting and Exposition Tulsa, Oklahoma October 22-25, 1990 Downloaded from SAE International by North Carolina State Univ, Sunday, September 16, 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. This consent is given on the condition, however, that the copier pay a $5.00 per article copy fee through the Copyright Clearance Center, Inc., Operations Center, 27 Congress St., Salem, MA 01 970 for copying beyond that permitted by Sections 107or 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. No part of this publication may be reproduced in any form, in an electronic retrieval system or otherwise, without the prior writ- ten permission of the publisher. ISSN 01 48-7191 Copyright 1990 Society of Automotlve Engineers, Inc. Positions and opinions advanced in this paper are those of the Persons wishing to submit papers to be arrsidered for presen- author(s)and not necessarily thoseof SAE. The author is solely tation or publication through SAE should send the manuscript responsible for the content of the paper. A process is available or a 300 word abstract of a proposed manuscript to: Secretary, by which discussions will be printed with the paper if it is Engineering Activity Board. SAE. published in SAE Transactions. For permission to publish this paper in full or in part, contact the SAE Publications Division. Rbrted In USA Downloaded from SAE International by North Carolina State Univ, Sunday, September 16, 2018A Study of Additive Effects ABSTRACT A new test machine has been developed which can evaluate vibration due to stick-slip using an actual full-scale clutch pack. Using this machine, a static breakaway friction coefficient measurement test method and a stick-slip test method have been established. Both methods have been shown to provide results which correlate with the results from both a full-scale assembly test and a vehicle shudder evaluation test. The evaluation of the frictional properties of commercial oils using these test methods showed that the static breakaway friction coefficient and the stick-slip properties have generally contradictory performance to each other for automatic transmission. The study of the frictional properties for typical additives and an analysis of the surface of the steel plates with ESCA (Electron Spectroscopy for Chemical Analysis) showed that the frictional properties are significantly affected by the additives adsorbed on the clutch plate sliding surf ace. FOR THE NEW ELECTRONICALLY-CONTROLLED A/T (automatic transmission), the ATF(automatic transmission fluid) is required to have a lower viscosity at low temperature, better frictional properties t.a provide smooth shifts and good friction durability (1) * . New friction characteristics have also become necessary for the recently developed hardware. ATF performance to prevent shudder is important especially for the systems which control hydraulic pressure during engagement or release of lock-up clutches (2). Therefore, the stick- slip property at low sliding speeds is becoming one of the m