Atf

A STUDY ON AUTOMATIC TRANSMISSION OVERHEATING PROBLEM

By

SHAROUL JAMBARI A dissertation submitted in partial fulfilment of the

requirements for the degree of Master of Science (Automotive Engineering)

Kulliyyah of Engineering International Islamic University Malaysia

MARCH 2009

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ABSTRACT

In this dissertation a study of heating problem in automatic transmission is investigated and discussed. Two important parameters that are temperature and pressure are measured. The possibility of using additives and oil coolers to reduce the temperature in automatic transmission is explored. In addition to that, the effect of pressure on the heating problem is also investigated. The testing procedure involved taking the measurements of pressure and temperature at four different points in the gearbox using the pressure and temperature sensors. Seven different types of testing were performed. Three tests were performed comparing different types of additives, two for comparing different types of oil coolers and two for comparing the new and old standard ATF. The results have shown that testing using additive reduced the temperature and maintained the pressure in automatic transmission. Testing using oil coolers also reduced the temperature and also reduced the pressure in automatic transmission. Therefore, we can conclude that using the additive is better than using oil cooler because of the pressure is maintained while reducing the temperature during the operating of automatic transmission.

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البحث ملخص

مت قياس عاملني مهمني ومها . ة إرتفاع احلرارة يف ناقل احلركة اآليل للسيارات يف هذه االطروحةمت دراسة ظاهر

. تبحث هذه الدراسة إمكانية إستخدام بعض االضافات ومربدات الزيت لتقليل احلرارة. احلرارة والضغط

رارة والضغط يف اربع مواقع مت أخذ قراءات احل. باالضافة اىل ذلك، مت أخذ التأثري على الضغط بنظر االعتبار

هناك سبعة طرق للفحوصات، ثالثة منها مع . خمتلفة يف صندوق التروس باستخدام جمس الضغط وجمس احلرارة

أي (وإثنان مع أنواع خمتلفة من مربدات الزيت ومت املقارنة مع املواصفات القياسية .أنواع خمتلفة من االضافات

. لنتائج، أنه باالمكان تقليل احلرارة والضغط باستخدام االضافاتأظهرت ا. احلديثة والقدمية) يت أف

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APPROVAL PAGE

I certify that I have supervised and read this study and that in my opinion; it conforms to acceptable standards of scholarly presentation and is fully adequate, in scope and quality, as a dissertation for the degree of Master of Science in Automotive Engineering. ……………………………………... Waleed Fekry Faris

Supervisor I certify that I have read this study and that in my opinion it conforms to acceptable standards of scholarly presentation and is fully adequate, in scope and quality, as a dissertation for the degree of Master of Science in Automotive Engineering. ….…………………………………… Kassim A. Abdullah Internal Examiner …….………………………………… Raed I.M.Kafafy Internal Examiner The dissertation was submitted to the Advanced Engineering and Innovation Centre and is accepted as a partial fulfilment of the requirements for the degree of Master of Science in Automotive Engineering. ……..…………………………………… Waleed Fekry Faris Director, Advanced Engineering and Innovation Centre

The dissertation was submitted to the Kulliyah of Engineering and is accepted as a partial fulfilment of the requirements for the degree of Master of Science in Automotive Engineering. ………………………………………….. Ahmad Faris Ismail Dean, Kulliyyah of Engineering

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DECLARATION

I hereby declare that this dissertation is the result of my own investigations, except

where otherwise stated. I also declare that it has not been previously or concurrently

submitted as a whole for any other degrees at IIUM or other institutions.

Sharoul Bin Jambari Signature.................................................. Date . ……………………….

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INTERNATIONAL ISLAMIC UNIVERSITY MALAYSIA

DECLARATION OF COPYRIGHT AND AFFIRMATION OF FAIR USE OF UNPUBLISHED

RESEARCH

Copyright © 2009 By Sharoul Bin Jambari. All Rights Reserved. STUDY ON AUTOMATIC TRANSMISSION OVERHEATING PROBLEM

No part of this unpublished research may be reproduced, stored in a retrieval system, or transmitted, in any form or by any means, electronic, mechanical, photocopying, recording or otherwise without prior written permission of the copyright holder except as provided below.

1. Any material contained in or derived from this unpublished research may only be used by others in their writing with due acknowledgement.

2. IIUM or its library will have the right to make transmit copies (print of

electronic) for institutional and academic purposes. 3. The IIUM library will have the right to make, store in a retrieval system

and supply copies of this unpublished research if requested by other universities and research libraries.

Affirmed by Sharoul Bin Jambari.

…………………………….. ………………………….. Signature Date

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In dedication to my beloved wife and children

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ACKNOWLEDGEMENTS

Bismillahirrahmaanirrahim, In the name of Allah, the most compassionate and the merciful. First and foremost, I am thankful and grateful to Allah SWT, the Creator and Sustainer of this whole universe, the Most Beneficent and the Most Merciful, for His guidance and blessings, and for granting me knowledge, patience and perseverance to accomplish this dissertation successfully. I take a great pride to express my sincere appreciation and gratitude to my supervisor, Asst Prof. Dr Waleed Fekry Faris, for his invaluable support, constant inspiration, expert guidance, encouragement and constructive criticism throughout this work. I have been fortunate to work under his guidance. I did learn a lot from his constant monitoring and his passion for perfection. It has been a wonderful experience working with him. I also would like to thank and appreciate to MARA and UniKL who support my studies. At last but not least, I also extend my thanks to my beloved wife and daughters who were the source of my motivation to work hard. Last but not least, I would like to thank all engineering faculty members especially Sister Rohamah for her support throughout the completion of my studies in IIUM.

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TABLE OF CONTENTS

Abstract ……………………………………………………………….................... ii Abstract in Arabic ………………………………………………………………… iii Approval Page …………………………………………………………..………… iv Declaration Page ………………………………………………………………….. v Copyright Page…………………………………………………………………….. vi Dedication ………………………………………………………………………………………….. vii Acknowledgements………………………………………………………………… viii Table of Contents………………………………………………………………….. ix List of Tables …………………………………………………………………….... xii List of Figures ……………………………………………………………………. xiii

CHAPTER 1: INTRODUCTION ……………………………………………… 1 1.1 Introduction……..……………………………………………..……….. 1 1.2 Research Objective ……………………………………………………. 2 1.3 Research Methodology............................................................................ 3 1.4 Thesis Outline…………………………………………………………. 4

CHAPTER 2: LITERATURREVIEW………………………………………… 6 2.1 Automatic Transmission Background…………………………………. 6 2.2 Automatic Transmission Arrangement………………………………… 7 2.3 Operating Principle of Automatic Transmission………………………. 9 2.4 Mechanism Automatic Transmission………………………………….. 12

2.4.1 Torque converter…………………………………………………. 12 2.4.2 Planetary gear set………………………………………………… 14 2.4.3 Multiple clutches and brakes…………………………………..… 16 2.4.4 One way clutch……………………………………………………17 2.4.5 Kickdown band brake……………………………………………..18 2.4.6 Hydraulic control system………………………………………… 18 2.4.7 Electronic control system………………………………………… 20 2.4.8 Non Electronic control system…………………………………… 21 2.4.9 Seal and Gasket………………………………………………….. 22 2.4.10 Common problem in automatic transmission………………….. 23

2.5 Automatic Transmission Cooling Technique………………………….. 25 2.5.1 Additive as the Cooling Agent…………………………………... 26 2.5.2 Oil Cooler as the Auxiliary Cooling system…………………….. 26 2.5.3 Transmission Oil Pan Special Design …………………………... 28

2.6 Previous Research on the Cooling Methods…………………………… 29 2.6.1 Additives inside Automatic Transmission…..…………………… 30 2.6.2 Viscosity Effect inside Automatic Transmission ……………….. 31 2.6.3 Auxiliary Oil Cooler ……………………………………………. 31 2.6.4 Control and prediction of transmission temperature…………….. 35 2.6.5 A shift control system for an automatic transmission…………… 38

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CHAPTER 3: METHODOLOGY………………………………………………. 41 3.1 Introduction……..……………………………………………………… 41 3.2 Equipment Setup…………………………………………………….… 41 3.2.1 Vehicle Specification…………………………………………….. 41 3.2.2 Chassis Dynamometer…………………………………………… 43 3.2.3 ATF Flushing Machine………………………………………….. 44 3.2.4 Digital Indicator…………………….…………………………..... 45 3.2.5 Temperature Sensor……………………………………………… 47 3.2.6 Pressure Sensors………………………………………………….. 48

3.3 Experimental Materials………………………………………………… 50 3.3.1 Different types of Additives……………………………………… 50 3.3.2 Aluminum and Steel types of Oil Coolers……………………..… 51 3.3.3 Standard Automatic Transmission Fluid………………………… 53

3.4 Experimental Method…...…………….……………………………….. 54 3.4.1 Start Testing…………………………………………………….... 54 3.4.2 Replacement of ATF……………………………………………... 54 3.4.3 Fix Instrumentation……………………………………………..... 56 3.4.4 Data Recording Process………………………………………….. 57 3.4.5 Experiment 1: Standard ATF only………………………………. 57 3.4.2 Experiment 2: Additive No 1 (med grade) + standard ATF……... 58 3.4.3 Experiment 3: Additive No 2 (low grade) + standard ATF……… 58 3.4.4 Experiment 4: Additive No 3 (high grade) + standard ATF…….. 59 3.4.5 Experiment 5: Aluminum Oil Cooler + standard ATF………….. 59 3.4.6 Experiment 6: Steel Oil Cooler + standard ATF………………… 59 3.4.7 Experiment 7: Used ATF (mileage ~ 15000 km)………………... 59 3.5 Cost Analysis………………………………………………………….. 60

CHAPTER 4: RESULTS AND DISCUSSIONS……………………………… 61

4.1 Introduction……..…………………………………………………..… 61 4.2 Experimental Results……………………………………………….…. 62 4.2.1 Experiment 1: Standard ATF only………………………………. 62 4.2.2 Experiment 2: Additive 1 + Standard ATF……………………… 64 4.2.3 Experiment 3: Additive 2 + Standard ATF……………………… 66 4.2.4 Experiment 4: Additive 3 + Standard ATF……………………… 68 4.2.5 Experiment 5: Aluminum Oil Cooler + Standard ATF…………. 70 4.2.6 Experiment 6: Steel Oil Cooler + Standard ATF……………….. 72 4.2.7 Experiment 7: Used ATF (mileage ~ 15000 km)……………….. 74 4.3 Analysis and Discussion………………………………………………. 77 4.3.1 Reducing Line…………………………………………………… 77 4.3.2 Torque Converter Line………………………………………….. 79 4.3.3 Transmission Outflow Line……………………………………… 81 4.3.4 Transmission Inflow Line……………………………………….. 83 4.3.5 Pressure Different at Cooling Line………………………………. 85 4.3.6 Temperature Different at Cooling Line…………………………. 86

4.3.7 Pressure Drop Cooling Line between Standard and Used ATF…. 87 4.3.8 Temperature Difference Cooling Line between Standard and Used ATF………………………………………………...… 88 4.3.9 Summary of Finding…………………………………………… 89

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CHAPTER 5: CONCLUSION AND RECOMMENDATION……………….. 90

5.1 Conclusion.............................................................................................. 90 5.2 Recommendation…................................................................................ 91

REFERENCES…………………………………………………………………… 93 APPENDIX……………………………………………………………………….. 96

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LIST OF TABLES

Table No. Page No.

3.1 Vehicle Specification 42

3.2 Chassis Dynamometer Specification 44

3.3 ATF Flushing Machine Specification 45

3.4 Digital Indicator Specification 47

3.5 Pressure Sensor Specification 49

3.6 Additives Specification 50

3.7 Oil Coolers Specification 52 3.8 Standard Repco ATF specification 54 3.9 Cost analysis 60 4.1 Summary of finding 89

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LIST OF FIGURES

Figure No. Page No.

1.1 Overheated clutch disc B and plate C 4

2.1 Rear wheel drive arrangement 8 2.2 Front wheel drive arrangement 9 2.3 Cut-view of Torque Converter 13 2.4 Side view of Planetary Gear system 14 2.5 Front view of Planetary gear system 14

2.6 Clutch packs 16 2.7 Kick-down Band Brake 18 2.8 Basic components of Hydraulic system 19 2.9 Pro-Blend Trans Cool Automatic Transmission Fluid (ATF) Additive 26 2.10 Auxiliary Oil Cooler 27

2.11 Special Transmission Oil Pan 27 2.12 Effect the temperature on the gearbox life 29

2.13 Standard line pressure for Mitsubishi gearbox (F4A23) 30

2.14 Plate type oil cooler 33

2.15 Makato’s Oil Cooler 35

2.16 Temperature controller for automatic transmission 37

2.17 Temperature effect on the shift quality 39

3.1 Proton Perdana V6 42

3.2 Chassis dynamometer – Communication console and Roller set 43 3.3 ATF Flushing Machine 45

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3.4 AD Scan & Thermo Scan 46 3.5 Thermocouple Type-K 48 3.6 Pressure Sensor 48 3.7 In-series installation of additional oil cooler 52 3.8 The right location of additional oil cooler 52 3.9 Process of Experimental Flowchart 55 3.10 Transmission outflow pressure line(T/M_O) and inflow pressure line (T/M_I) locations 56 3.11 Reducing pressure line (RED) and Torque converter pressure line

(T/C) location 56 4.1 Pressure vs. Shifting Gear (Experiment no 1) 62 4.2 Temperature vs. Shifting Gear (Experiment no 1) 63 4.3 Pressure vs. Shifting Gear (Experiment no 2) 64 4.4 Temperature vs. Shifting Gear (Experiment no 2) 65 4.5 Pressure vs. Shifting Gear (Experiment no 3) 66 4.6 Temperature vs. Shifting Gear (Experiment no 3) 67 4.7 Pressure vs. Shifting Gear (Experiment no 4) 68 4.8 Temperature vs. Shifting Gear graph for Experiment no 4 69 4.9 Pressure vs. Shifting Gear (Experiment no 5) 70 4.10 Temperature vs. Shifting Gear (Experiment no 5) 71 4.11 Pressure vs. Shifting Gear (Experiment no 6) 72 4.12 Temperature vs. Shifting Gear (Experiment no 6) 73 4.13 Pressure vs. Shifting Gear (Experiment no 7) 74 4.14 Temperature vs. Shifting Gear (Experiment no 7) 75 4.15 Comparison Pressure vs. Shifting Gear at reducing line 77 4.16 Comparison Temperature vs. Shifting Gear at reducing line 78

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4.17 Comparison Pressure vs. Shifting Gear at torque converter 79 4.18 Comparison Temperature vs. Shifting Gear at torque converter 80 4.19 Comparison Pressure vs. Shifting Gear at transmission outflow line 81 4.20 Comparison Temperature vs. Shifting Gear at transmission outflow 82

line 4.21 Comparison Pressure vs. Shifting Gear at transmission inflow line 83 4.22 Comparison Temperature vs. Shifting Gear at transmission inflow 84

line 4.23 Comparison Pressure vs. Shifting Gear at cooling system 85 4.24 Comparison Temperature vs. Shifting Gear at cooling system 86 4.24 Comparison Pressure vs. Shifting Gear for used ATF 87 4.24 Comparison Temperature vs. Shifting Gear for used ATF 88

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CHAPTER 1

INTRODUCTION 1.1 INTRODUCTION

The use of automatic transmission in motor vehicles nowadays is increasing

drastically. Automatic transmission is an automobile gearbox that can change gear

ratios automatically as the car moves, thus freeing the driver from having to shift

gears manually. People feel that driving a vehicle with automatic transmission will

give them comfort and make them less fatigued. Therefore, the demand for repairing

automatic gearboxes is also increasing. People who are using automatic transmission

vehicles normally lack the knowledge of how to take care of their cars. Owners of the

vehicles should be aware of preventive maintenance. Those who are engaged in severe

driving need to equip their vehicles with an additional cooling system to reduce the

heat generated during the running of vehicles. Most of the transmission troubles start

from the overheating of its fluid. The transmission can overheat under heavy loads,

such as towing a heavy trailer, rocking the vehicle from the snow, being in severe

traffic jam in hot weather, racing and speeding.

Overheating means the increase in temperature leading to reduced efficiency,

damage or even destruction. At higher temperatures the transmission fluid burns,

losing its lubricating qualities and becomes oxidized leaving deposits all over the

inside of the transmission. Exposed to the heat, the rubber seals and gaskets inside the

transmission become hardened and this causes leaks. The metal parts warp and lose

their strength. All this, sooner or later, results in transmission failure.

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Recently, many research studies and inventions have been carried out to

overcome the problem of transmission overheating. For example, the use of

transmission cooler additives, oil coolers, heat exchangers, electrical fans, cooling

filters and fin-design oil pans. Most of the above mentioned systems have shown that

they can reduce the temperature inside the automatic transmission to 35°C during

severe driving. This is considered good enough according to Canter (2005) who found

out that a reduction of only 10°C to 12°C in the temperature of the oil leads to a

dramatic increase in the life of the automatic transmission.

The thermocouple is used to take the automatic transmission fluid temperature

at four points; the torque converter line, the reducing line, the cooling outflow line and

the cooling inflow line. Then, temperature data at different operating conditions is

compared for different types of additional cooling methods. Besides that, the pressure

reading is recorded to see the differences.

1.2 OBJECTIVES AND SCOPE OF THE PROJECT

The main objective of this thesis is to study the effectiveness of using different types

of additional cooling methods in the automatic transmission vehicle.

This project focuses on the problem of overheating of automatic transmission

that occurs during heavy duty or severe driving. This project focuses on the use of

different types of additives and oil coolers. In this project the gearbox of a local brand

vehicle, Proton Perdana V6 is used for all experiments.

This study is carried out to determine the best system that can be implemented

in automatic transmissions at the lowest cost that can be affordable to low income

customers to upgrade their system.

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1.3 AUTOMATIC TRANSMISSION FLUID (ATF)

The automatic transmission hydraulic system requires special fluid for the

transmission to operate properly and provide a long service life. A filter is used to

clean the fluid and prevent wear and tear from occurring to the components of the

transmission. Oil to water cooler is also provided in the radiator of the cooling system

in order to remove excessive heat from the fluid. In addition, since the engine cooling

system reaches operating temperature quicker than the transmission, the cooler helps

to warm up the transmission fluid.

Automatic transmission fluid is a high-grade petroleum product containing

several kinds of special chemical additives. This fluid plays various important

functions in the automatic transmission. It is pressurized by the transmission oil pump

and fed to the torque converter and transmits the torque generated by the engine to the

transmission. The pressurized ATF flows through the passages and valves to operate

the clutches and brakes that control the planetary gears and other moving parts. In

addition, it cools, cleans and lubricates all moving parts. In order to perform all these

functions for thousands of kilometres and deliver satisfactory performance, a number

of additives are used to deal with the environment of close tolerances, high heat and

rotating components.

The possible areas of deteriorations of ATF are an increase in oil temperature

due to overheating of the engine, slippage of the hydraulic multi-plate clutch in the

automatic transmission and the degradation of the ATF itself over a long period of

use.

Since heat is generated in the torque converter of the transmission, the

temperature of ATF inevitably increases. It is, therefore, necessary to feed the ATF

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out of the torque converter for cooling. In a common arrangement, the ATF is fed

from the torque converter to the cooling pipeline which is equipped in the radiator.

An increase in the temperature of ATF will certainly result in its deterioration.

The result of deterioration of ATF appears in the form of discoloration.

Figure 1.1: Overheated clutch disc B and plate C

1.5 THESIS OUTLINE

This thesis is organized into five chapters. The first chapter of this thesis provides

some essential introduction about the use of automatic transmission and its problems.

Basic information about the automatic transmission fluid (ATF) is also briefly

explained.

In Chapter 2, the background of the automatic transmission is explained in

detail such as the operations and functions of the components. The automatic

transmission cooling methods and temperature control are explored and the literature

review of automatic transmission is given.

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The methodology of the research is described in detail in Chapter 3. The results

are tabulated discussed and compared between two methods of analysis in Chapter 4.

Finally, conclusions and recommendations are presented in Chapter 5.

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CHAPTER 2

LITERATURE REVIEW

2.1 AUTOMATIC TRANSMISSION BACKGROUND

The definition of automatic transmission is an automobile gearbox that can change

gear ratios automatically as the car moves, thus freeing the driver from having to shift

gears manually.

Oldsmobile's 1940 models featured Hydra-Matic drive, making this lineup the

first vehicles with fully automatic transmission. It provided true clutchless driving

with four forward speeds. Its fluid coupling between engine and transmission

eliminated the clutch and its associated foot work. In the early 50s, Olds produced its

millionth Oldsmobile with automatic transmission, demonstrating Hydra-Matic's rapid

rise in popularity.

The first hydraulic automatics were introduced by General Motors, Chrysler

and Borg-Warner in the early 1950s. These early models only provided 2 forward

speeds, and were not able to handle much torque at first, but 3-speed models followed

quickly. In about 1980, the first big change for hydraulic automatic transmission

designs in years came. The addition of an overdrive capability helped increase fuel

economy considerably on long journeys.

The second was the torque converter equipped with damper clutch. This

concept first appeared in the early 1980s with the advent of engine computers, and

involved a solenoid-controlled clutch inside the torque converter, which would lock its

input to its output when activated. The idea was to eliminate the drag and inefficiency

caused by the fluid in the converter when operating at high speeds. The damper clutch

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was an effort to improve fuel economy with a relatively minor modification to the

transmission.

As the electronic control unit engine computers became more and more

capable, even more of the valve body's functionality was offloaded to them. These

transmissions, introduced in the late 1980s and early 1990s, remove almost all of the

control logic from the valve body, and place it in the hands of the engine computer, in

this case, solenoids turned on and off by the computer control shift patterns and gear

ratios, rather than the spring-loaded valves in the valve body. This allows for more

precise control of shift points and shift quality, and also allows semi-automatic

control, where the driver tells the computer when to shift.

2.2 AUTOMATIC TRANSMISSION ARRANGEMENT

The transmission is a device that is connected to the back of the engine and sends the

power from the engine to the drive wheels. An automobile engine runs at its best at a

certain RPM (revolutions per minute) range and it is the transmission's job to make

sure that the power is delivered to the wheels while keeping the engine within that

range. It does this through various gear combinations. In first gear, the engine turns

much faster in relation to the drive wheels, while in high gear the engine is loafing

even though the car may be going in excess of 70 km/h. In addition to the various

forward gears, a transmission also has a neutral position which disconnects the engine

from the drive wheels, and reverse, which causes the drive wheels to turn in the

opposite direction allowing you to back up. Finally, there is the PARK position. In

this position, a latch mechanism is inserted into a slot in the output shaft to lock the

drive wheels and keep them from turning, thereby preventing the vehicle from rolling.

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There are two basic types of automatic transmissions based on whether the

vehicle is rear wheel drive or front wheel drive. On a rear wheel drive car as shown in

figure 2.1, the transmission is usually mounted to the back of the engine and is located

under the hump in the centre of the floorboard alongside the accelerator pedal

position. A drive shaft connects the rear of the transmission to the final drive which is

located in the rear axle and is used to send power to the rear wheels. Power flow in

this system is simple and straight forward going from the engine, through the torque

converter, then through the transmission and drive shaft until it reaches the final drive

where it is split and sent to the two rear wheels.

Figure 2.1: Rear wheel drive arrangement

On a front wheel drive car as shown in figure 2.2, the transmission is usually

combined with the final drive to form what is called a transaxle. The engine on a front

wheel drive car is usually mounted sideways in the car with the transaxle tucked under

it on the side of the engine facing the rear of the car. Front axles are connected

directly to the transaxle and provide power to the front wheels. In this example, power

flows from the engine, through the torque converter to a large chain that sends the

power through a 180 degree turn to the transmission that is side along the engine.

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From there, the power is routed through the transmission to the final drive

where it is split and sent to the two front wheels through the drive axles.

Figure 2.2: Front wheel drive arrangement

2.3 OPERATING PRINCIPLE OF AUTOMATIC TRANSMISSION

Automatic transmissions contain mechanical systems, hydraulic systems, electrical

systems and computer controls, all working together in perfect harmony which goes

virtually unnoticed until there is a problem. This article will assist the reader to

understand the concepts behind what goes on inside these technological marvels and

what goes into repairing them when they fail.

The modern automatic transmission consists of many components and systems

that are designed to work together in a symphony of clever mechanical, hydraulic and

electrical technology that has evolved over the years into what many mechanically

inclined individuals consider to be an art form. We try to use simple, generic

explanations where possible to describe these systems but, due to the complexity of

some of these components, the reader needs make an effort to visualize their

operation.