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 2002-01-2819 Development of a Belt CVT Fluid Test Procedure Using the VT20/25E Belt Box for the DEX-CVT® Specification Chris Morgan and Roy Fewkes General Motors Corporation Steven D. Marty Southwest Research Institute Reprinted From : Lubricants (SP-1722) Powertrain & Fluid Systems Conference & Exhibition San Diego, California USA October 21-24, 2002Downloaded from SAE International by University of British Columbia, Tuesday, July 31, 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: [email protected]: 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 [email protected] ISSN 0148-7191Copyright © 2002 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 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 British Columbia, Tuesday, July 31, 20182002-01-2819 Development of a Belt CVT Fluid Test Procedure Using the VT20/25E Belt Box for the DEX-CVT® Specification Chris Morgan and Roy Fewkes General Motors Corporation Steven D. Marty Southwest Research Institute Copyright © 2002 Society of Automotive Engineers, Inc. ABSTRACT The introduction of the continuously variable transmission (CVT) by General Motors required the introduction of a test to evaluate fluid for the ECOTEC VTi transmission. With assistance from Van Doorne’s Transmissie (VDT), the belt and sheave supplier for the transmission, a rig was constructed to test fluids in a transmission-like environment wi thout the variability of in-vehicle testing. The test schedule includes testing for fluid friction coefficient, shear stability, and wear rating and is currently subject to further work aimed at confirming repeatability and discrimination. Once confirmed, the new procedure will become part of the DEX-CVT® specification for the new service fluids for the VT20/25E transmissions. INTRODUCTION The introductions of the Opel Astra and Saturn VUE with the ECOTEC VTi, push belt continuously variable transmission (CVT), create a need for a test that will evaluate fluid durability and compatibility with the variator system of the VT20/25E transmissions. The current VT20/25E belt box test stands, which are mostly intended for hardware verification purposes, have large fluid sumps, preventing any signi ficant aging of the fluid. Another problem with the current VT20/25E belt box test stands is that they are all owned and controlled by Van Doorne’s Transmissie b.v. (VDT) and located in Holland.[1] A test stand of the same general setup as the VDT stands was assembled, using a VDT supplied belt box with a smaller fluid reservoir, to give the test rig a fluid capacity that resembled the VTi since the rig is to be used primarily for fluid validation, not hardware testing. This new rig was assembled for General Motors (GM) at Southwest Research Institute (SwRI) in San Antonio, Texas. CVT lubricant performance is a topic of increasing interest. The fir