noise vibration harshness D D nvh principles and diagnosis student reference book COURSE CODE: 30S03T0 ORDER NUMBER: FCS-13423-REF OCTOBER, 2004 DELIVER Ford Customer Service Division Technical Training IMPORTANT SAFETY NOTICE Appropriate service methods and proper repair procedures are essential for the safe, reliable operation of all motor vehicles, as well as the personal safety of the individual doing the work This manual provides general directions for accomplishing service and repair work with tested, effective techniques Following them will help assure reliability There are numerous variations in procedures, techniques, tools and parts for servicing vehicles, as well as in the skill of the individual doing the work This manual cannot possibly anticipate all such variations and provide advice or cautions as to each Accordingly, anyone who departs from instructions provided in this manual must first establish that he compromises neither his personal safety nor the vehicle integrity by his choice of methods, tools or parts As you read through the procedures, you will come across NOTES, CAUTIONS, and WARNINGS Each one is there for a specific purpose NOTES give you added information that will help you to complete a particular procedure CAUTIONS are given to prevent you from making an error that could damage the vehicle WARNINGS remind you to be especially careful in those areas where carelessness can cause personal injury The following list contains some general WARNINGS that you should follow when you work on a vehicle • • Always wear safety glasses for eye protection • • • To prevent serious burns, avoid contact with hot metal parts such as the radiator, exhaust manifold, tail pipe, catalytic converter and muffler Be sure that the ignition switch is always in the OFF position, unless otherwise required by the procedure • • Do not smoke while working on the vehicle Set the parking brake when working on the vehicle If you have an automatic transmission, set it in PARK unless instructed otherwise for a specific service operation If you have a manual transmission it should be in REVERSE (engine OFF) or NEUTRAL (engine ON) unless instructed otherwise for a specific service operation • Keep hands and other objects clear of the radiator fan blades Electric cooling fans can start to operate at any time by an increase in underhood temperatures, even though the ignition is in the OFF position Therefore, care should be taken to ensure that the electric cooling fan is completely disconnected when working under the hood Use safety stands whenever a procedure requires you to be under the vehicle • Operate the engine only in a well-ventilated area to avoid the danger of carbon monoxide • Keep yourself and your clothing away from moving parts when the engine is running, especially the fan and belts To avoid injury, always remove rings, watches, loose hanging jewelry, and loose clothing before beginning to work on a vehicle Tie long hair securely behind your head The recommendations and suggestions contained in this manual are made to assist the dealer in improving his dealership parts and/or service department operations These recommendations and suggestions not supersede or override the provisions of the Warranty and Policy Manual, and in any cases where there may be a conflict, the provisions of the Warranty and Policy Manual shall govern The descriptions, testing procedures, and specifications in this handbook were in effect at the time the handbook was approved for printing Ford Motor Company reserves the right to discontinue models at any time, or change specifications, design, or testing procedures without notice and without incurring obligation Any reference to brand names in this manual is intended merely as an example of the types of tools, lubricants, materials, etc recommended for use Equivalents, if available, may be used The right is reserved to make changes at any time without notice WARNING: Many brake linings contain asbestos fibers When working on brake components, avoid breathing the dust Breathing the asbestos dust can cause asbestosis and cancer Breathing asbestos dust is harmful to your health Dust and dirt present on car wheel brake and clutch assemblies may contain asbestos fibers that are hazardous to your health when made airborne by cleaning with compressed air or by dry brushing Wheel brake assemblies and clutch facings should be cleaned using a vacuum cleaner recommended for use with asbestos fibers Dust and dirt should be disposed of in a manner that prevents dust exposure, such as sealed bags The bag must be labeled per OSHA instructions and the trash hauler notified as to the contents of the bag If a vacuum bag suitable for asbestos is not available, cleaning should be done wet If dust generation is still possible, technicians should wear government approved toxic dust purifying respirators OSHA requires areas where asbestos dust generation is possible to be isolated and posted with warning signs Only technicians concerned with performing brake or clutch service should be present in the area Copyright © 2001 Ford Motor Company Produced and Coodinated by Technical Service Support Operations Ford Customer Service Division October, 2004 SERVICE STANDARDS Mission Statement: All dealership personnel will treat every customer as a potential lifetime purchaser, communicating a professional image which embraces honesty and concern for customer wants and needs Dealer-to-Customer Service Standards: Appointment available within one day of the customer’s requested service day Write-up begins within four minutes of arrival Service needs courteously identified, accurately recorded on Repair Order, and verified with customer Vehicles serviced right on the first visit Service status provided within one minute of inquiry Vehicle ready at agreed upon time Thorough explanation of work done, coverages and changes These seven service standards provide a process and product value that are compelling reasons for owners to purchase and repurchase Ford or Lincoln-Mercury products These standards also help to attract new owners through favorable testimonials and improved owner satisfaction Standard “Fix It Right the First Time, on Time.” The technician is the most important player when it comes to Standard #4 Why Customers tell us “Fixing It Right the First Time, on Time” is one of the reasons they would decide to return to a dealer to buy a vehicle and get their vehicles serviced Technician Training It is our goal to help the technician acquire all of the skills and knowledge necessary to “Fix it Right the First Time, on Time.” We refer to this as “competency.” Technician’s Role Acquire the skills and knowledge for competency in your specialty via STST New Model — Self Study — Self Study — Ford Multimedia Training (FMT) — Instructor Led — Instructor Led The Benefits The successful implementation of standards means — Satisfied customers — Repeat vehicle sales — Repeat service sales — Recognition that Ford and Lincoln/Mercury technicians are “the Best in the Business” TABLE OF CONTENTS WARM UP QUIZ Warm Up-1 NVH Warm Up Quiz Warm Up-1 Instructor’s Information Sheet Warm Up-1 Instructor’s Answer Sheet Warm Up-3 INTRODUCTION Intro-1 Introduction Intro-1 Evaluation Strategy Intro-1 DAY ONE: INTRODUCTION TO NVH 1-1 What is NVH? 1-2 Fundamentals of NVH 1-3 Definition of Vibration 1-8 Definition of Noise 1-13 Definition of Harshness 1-15 Worksheet A (at Workstation 1) Identifying Engine Noises (On-Vehicle) Student’s Answer Sheet 1-20 DAY ONE: NVH DIAGNOSTIC TOOLS AND EQUIPMENT 2-1 Vibration Diagnostic Tools 2-2 Noise Diagnostic Tools 2-18 Worksheet B (at Workstation 1) Identifying Vehicle Noise (On-Vehicle) Student’s Answer Sheet 2-29 Worksheet C (at Workstation 2) Measuring Frequency and Amplitude (On-Vehicle) Student’s Answer Sheet 2-33 Worksheet D (at Workstation 3) Measuring Frequency (Bench) Student’s Answer Sheet 2-37 Worksheet E (at Workstation 4) NVH Terminology and Tools Student’s Answer Sheet 2-41 Noise, Vibration, and Harshness October, 2004 i TABLE OF CONTENTS DAY TWO: DIAGNOSIS OF NVH CONCERNS 3-1 Diagnostic Process 3-2 Diagnosis of Vibration Concerns 3-15 Worksheet F (at Workstation 1) Diagnosing Vehicle Vibrations (On-Vehicle) Student’s Answer Sheet 3-55 Worksheet G (at Workstation 2) Diagnosing Vehicle Vibrations (On-Vehicle) Student’s Answer Sheet 3-59 Worksheet H (at Workstation3) Vibrate 5.0 (Bench) Student’s Answer Sheet 3-63 Worksheet I (at Workstation 4) Frequency Calculations (Navigation) Student’s Answer Sheet 3-69 Diagnosis of Noise Concerns 3-73 Diagnosis of Harshness Concerns 3-78 DAY THREE Day Three-1 Worksheet J (at Workstation 1) Diagnosing Vehicle Noise (On-Vehicle) Student’s Answer Sheet Day Three-3 Worksheet K (at Workstation 2) Diagnose A Vehicle Vibration (On-Vehicle) Student’s Answer Sheet Day Three-7 Worksheet L (at Workstation 4) Diagnosing Noise and Vibration Concerns (Navigation) Student’s Answer Sheet Day Three-11 NVH GLOSSARY Glossary-1 APPENDIX Appendix-1 “Write-Up” Job Aid Appendix-1 Courtesy Inspection Appendix-3 NVH Diagnostic Guide Appendix-5 Frequency and RPM Calculations Appendix-7 Day One – Homework Appendix-9 Day Two – Homework Appendix-11 ii October, 2004 Noise, Vibration, and Harshness WARM UP QUIZ NVH WARM UP QUIZ STUDENT’S ANSWER SHEET NAME: Harshness is a term commonly used to describe: A a hard steering condition due to lack of power steering fluid B an unpleasant sound found to be abnormal to the vehicle’s characteristics C a firmer than usual response from the suspension system D none of the above Which of the following modes is used to monitor engine RPM with a New Generation Star (NGS) Tester? A Output State Commands B Retrieve and Clear Continuous Memory C On Demand Self Test D PID/Data Monitor and Record Every time a vibrating component goes through its complete range of motion and returns to the starting point is called a: A cycle B frequency C pitch D period The ChassisEAR is used to detect: A ultrasonic sounds B the frequency of a repetitive vibration C the origin of a noise D only the frequency of a noise Which of the following is critical for vibration diagnosis? A vibration frequency B engine RPM C vehicle speed D all of the above The number of times an engine fires a cylinder with each crankshaft revolution is equal to: A One-half the number of cylinders B Three-fourth the number of cylinders C Total number of cylinders D Twice the number of cylinders Noise, Vibration, and Harshness October, 2004 Warm Up-3 WARM UP QUIZ NVH WARM UP QUIZ STUDENT’S ANSWER SHEET (Continued) Which of the following terms indicates the actual amount of component movement during a vibration? A frequency B amplitude C pitch D cycle Which of the following is the correct order of vibration transfer path A Conductor to Reactor to Originator B Reactor to Conductor to Originator C Originator to Conductor to Reactor D Originator to Reactor to Conductor Runout and imbalance conditions are affected mostly by: A speed B torque C power D all of the above 10 To interrupt the transmission of a normal engine vibration from reaching the passenger compartment, a technician would: A eliminate the originator of the vibration B repair the engine vibration C replace or realign faulty conductors of the vibration D all of the above 11 Two high spots on a tire rotating 10 times a second has a _ order vibration of 20 Hz A first B second C third D half 12 All of the following are vibration diagnosis tools except: A Electronic Vibration Analyzer (EVA) B Sirometer C ChassisEAR D Reed Tachometer Warm Up-4 October, 2004 Noise, Vibration, and Harshness WARM UP QUIZ NVH WARM UP QUIZ STUDENT’S ANSWER SHEET (Continued) 13 What is the ChassisEAR? How does it operate? _ _ _ _ 14 How you get engine rpm readings from the New Generation Star Tester (NGS)? _ _ _ 15 Define noise Define vibration Define harshness _ _ _ Noise, Vibration, and Harshness October, 2004 Warm Up-5 NOTES NVH GLOSSARY Drivetrain All power transmitting components from the engine to the wheels, including the clutch or torque converter, the transaxle, the driveline, and the drive axle Drone A sustained tone at a higher pitch than boom EngineEAR Trade name of an electronic noise detection device It consists of an earphone head-set, adjustable amplifier and a noise sensor It is primarily used to isolate engine noises, vacuum leaks (noise), body squeaks, and rattles Engine Imbalance Engine imbalance is created when any engine component or accessory that rotates is out of balance or has excessive runout Engine Vibration Any vibration caused by the rotating components of the engine or the related accessories Engine vibrations can occur at any vehicle speed Electronic Vibration Analyzer (EVA) An electronic tool that senses and displays vibration frequencies and amplitudes First Order Vibration A vibration frequency that is produced only once during a complete revolution or cycle Forced Vibration A vibration that only occurs as long as the force (originator) that initiated the vibration remains Free Vibration The continued vibration of an object after the outside force (originator) is removed Frequency The rate at which a cycle occurs within a given time G-force The additional load or weight produced in an object during acceleration When measuring the level or amplitude of a vibration without sound, the unit G is added to associate the force of the vibration to gravity This is similar to measuring the weight of an object, which is also a function of gravity An object which has a weight of 10 pounds at 1-G will yield a weight of 20 pounds when a 2-G force is applied Grunt on Acceleration Grunt on acceleration is a raspy sound and momentary vibration in the floor pan during acceleration or following a braking stop Harshness Harshness refers to the vehicle’s ride It is normally used to describe a firmer than usual response from the suspension system High Speed Shake Vibration that produces a visible shake and pumping feel in the steering wheel, accelerator pedal, seat, and floor Common vehicle speeds range above 45 mph (72 km/h) Howl A mid-range pitch noise that may be heard at any speed Usually, it can be affected by acceleration or deceleration Hum A low-pitch noise often accompanied by a vibration felt in the floor pan Hz Hertz, a frequency of one cycle per second Glossary-2 October, 2004 Noise, Vibration and Harshness NVH GLOSSARY Imbalance Improper weight distribution, or heavier on one side than the other In a rotating component, often causes vibration Intensity The physical quality of sound that relates to the strength of the vibration (measured in decibels) The higher the amplitude of the sound, the higher the intensity, and vice versa Natural Frequency The natural frequency refers to the frequency range during which an object tends to vibrate Natural frequency varies depending on the material composition, mass, and size of an object Noise An unpleasant sound found to be abnormal to the vehicle’s operating characteristics NVH Noise, vibration, and harshness Order of Vibration The number of times a vibration occurs during one complete cycle Origin or Originator The component, or part that first initiates a vibration Phase Referring to the rotational positions of the various elements of a driveline Pitch The physical quality of sound that relates to its frequency Pitch increases as frequency increases, and vice versa Radial/Lateral Radial is in the plane of rotation Lateral is at 90 degrees to the plane of rotation Rattle A rapid succession of short sharp noises Reactor The component, or part that receives a vibration from an originator and conductor and reacts to the vibration by moving Reed Tachometer A mechanical tool that consists of several metal reeds Each reed is tuned to react to a different vibration frequency It is used to measure the frequency of a vibrating component Roughness Vibration with a slightly higher frequency than shake, 20 to 50 Hz RPM Revolutions per minute Rumble Low-pitch noise often loudest during turns Can usually be identified as front or rear in origin Second Order Vibration Vibration frequencies that are produced twice during a complete revolution or cycle Shake Low frequency vibration usually accompanied by visible movement of components Mid-car shake – Mid-car shake is a low frequency vibration (5 to 20 Hz) that causes the vehicle interior elements (seat, steering column, and so on) to shake Usually most noticeable in an overdrive gear under light acceleration High speed shake – High speed shake produces a visible shake and pumping feel in the steering wheel, accelerator pedal, seat, and floor This condition is sometimes seen as front-end sheet metal flutter Common vehicle speeds range above 45 and 50 mph (72 and 80 km/h) Noise, Vibration, and Harshness October, 2004 Glossary-3 NVH GLOSSARY Shimmy The wobble of a front wheel around the steering axis Shudder This is a low frequency vibration that is felt in the floor and/or steering wheel during light brake application Common vehicle speeds range between and 40 mph (13 and 64 km/h) Squeak An intermittent sound that is of high pitch and short duration Steering Wheel Nibble Low-frequency vibration characterized by a slight or partial oscillation of the steering wheel Tip-in Moan A light moaning noise heard when the vehicle is lightly accelerated, usually between 40 and 100 km/h (25 and 65 mph) Torsional Vibration Low frequency vibration that is produced by components while they are under a twisting strain Torsional vibration is felt in the seats and floor of the vehicle and is heard as a rumbling sound The vibration is most noticeable during steady, hard acceleration Ultrasonic Leak Detector A diagnostic tool that consists of a high frequency generator (tone generator) and receiver The frequency generator is placed inside a closed vehicle The receiver detects the frequencies that escape through gaps and leaks Universal Joints A double-hinged connection between two shafts which permits one to drive the other, although both shafts operate at intersecting angles Vibration A shaking or trembling that can be felt High-speed vibrations occur at speeds higher than 45 to 50 mph (72 to 80 km/h) Low-speed vibrations occur at speeds below 45 to 50 mph (72 to 80 km/h) Whine A high pitch noise that may be heard at any speed It is usually (but not always) unaffected by accelerating and decelerating Glossary-4 October, 2004 Noise, Vibration and Harshness “WRITE-UP“ JOB AID YES SEE SMELL YES FEEL REPAIR ORDER # Engine Compartment Front of Vehicle VEHICLE SYMPTOM AREA Conditional Daily A.M P.M Always HOW OFTEN? Accel Light Gear Selection Idle Start Up VEHICLE OPERATING MODE Hauling 4x4 Windows Open (define below) Accessories On VEHICLE CONDITIONS 40-49 30-39 20-29 10-19 1-9 Shifting Down Hills Up Hills Over Bumps Turning Right Turning Left Temp–70˚-89˚ Temp–50˚-69˚ Temp–33˚-49˚ Below Freezing (20˚-32˚) Below Freezing (0˚-19˚) _˚ Below Zero CUSTOMER CONCERN # Dash Weekly Accel Moderate Towing AMBIENT CONDITION Steering Wheel Monthly Accel Heavy VEHICLE WHEN SPEED (mph) VEHICLE IS? Accelerator Pedal Intermittent Sunny Brake Pedal In Traffic Temp–90˚+ 60-69 Parked Other (define below) Dry 50-59 Deceleration 70+ Wet/Humid Snow Plowing Neutral ENGINE TEMP Steady Speed Seat Reverse Unknown Rear of Vehicle Stopping/Braking Under Vehicle Normal Cold Snow Rain Windy Floor Pan Top of Vehicle Other (define below) VIN NUMBER WHAT THE CUSTOMER SAID Ice YES OASIS SYMPTOM CODE(S) VERIFIED WITH CUSTOMER TECHNICIAN QC MANAGER SERVICE MANAGER SHOP FOREMAN SERVICE ADVISOR DEALER VERIFICATION Hot NO Clutch Pedal A SENSE OF CUSTOMER SATISFACTION SATISFACTION SPECIFIC SENSE IDENTIFICATION AND LOCATION ON VEHICLE OF CUSTOMER SYMPTOM(S) INSTRUCTIONS: Check below sense affected and location of concern on the generic vehicle illustration (darken the vehicle area) Plus circle appropriate responses to the right HEAR YES A B ENGINE FRONT YES C D E F NOTE: Shaded backgrounds indicate caution areas Selection of two or more caution areas "flag" difficult repairs In general, shaded areas are the more difficult to verify and repair, and require all applicable columns to be completed + MID REAR CARGO Appendix-1 October, 2004 Noise, Vibration, and Harshness NOTES Appendix-2 October, 2004 Noise, Vibration, and Harshness X = Not OK L R Yr & Model ? = See Tech Name COURTESY INSPECTION ✓ = OK LIGHTS Head Lamps Front Signals Hazard Lights Brake Lamps Rear Signals License Light Trunk Drive Belt(s) (See Mileage Below) TECHNICIAN Cupped Tire Worn Out Alignment Damaged Tire Cupping Tread Depth 32nd’s Replacement Other See Repair Order for Customer Authorization Align Wear Rotation Leakage Wear From Incorrect Toe Angle WIPER WEAR OK RECOMMEND (circle): Right Rear Left Rear Left Front Right Front Position Wear From Incorrect Camber Rear Wiper Windshield Wipers Service Advisor _ Mileage Phone Exhaust/Heat Shields Radiator & Heater Hoses UNDER HOOD Shocks/Struts Battery & Cables UNDER VEHICLE Half Shaft Boots Engine Compartment Light ❏ Change engine oil and filter ❏ Perform multi-point inspection ❏ Inspect brake system • Technician will: • Inspect: friction material, caliper operation, rotors, drums, hoses and connections • Inspect parking brake for damage and proper operation ❏ Inspect engine cooling system, hoses and clamps ❏ Lubricate all hinges & latches, door locks and door weatherstrips ❏ Rotate tires (if required) ❏ Change engine coolant (not required at 15,000 miles) ❏ Replace platinum tipped spark plugs (only at the 105,000 mile interval) ❏ Inspect non-neoprene accessory drive belt (only at the 105,000 mile interval) 30,000 / 60,000 / 90,000 / 120,000 Miles Dome OTHER (Define) Oil/Fluid Leaks TIRE WEAR ❏ Change engine oil and filter ❏ Perform multi-point inspection ❏ Inspect brake system ❏ Visually inspect battery & clean terminals ❏ Inspect engine cooling system, hoses and clamps ❏ Lubricate all door hinges/latches/locks/weatherstrips ❏ Perform automatic transmission/transaxle service ❏ Replace air cleaner/filter ❏ Replace fuel filter (Lt Truck and S.U.V.) ❏ Inspect and/or repack front wheel bearings (4 x Lt Trucks, S.U.V.s and Aspire) ❏ Inspect clutch operation ❏ Rotate tires (if required) ❏ Replace PCV valve (only at 60,000 & 120,000 miles) ❏ Replace fuel filter (cars and vans not required but recommended at 60,000 & 120,000 miles) ❏ Inspect evaporative fuel system hoses and tubes (only at 60,000 and 120,000 miles) ❏ Replace non-platinum tipped spark plugs (see scheduled maintenance guide) ❏ Inspect neoprene accessory drive belt (not required at 30,000 miles) QUALITY CARE MAINTENANCE – RECOMMENDED ITEMS 95-98 MODELS ONLY (Always refer to the Scheduled Maintenance Guide for additional recommended maintenance) Select either 5,000 or 3,000 mile service interval based on customer’s driving habits ❏ Change engine oil and filter ❏ Perform multi-point inspection • Technician will check & fill: • Windshield washer fluid • Coolant recovery reservoir fluid • Brake fluid • Power steering fluid • Transmission fluid • x transfer case, front axle & clutch reservoir fluid (truck) • Check & adjust air pressure in all tires (including spare) • Check exhaust system • Check operation of horn, exterior lamps, turn signals, and hazard warning lights • Check radiator, heater & AC hoses for leaks or damage • Check windshield washer spray & wiper operation • Inspect half shaft boots, if equipped • Check & lubricate steering, steering linkage, suspension, U-joints (only if equipped with grease fittings), slip yoke (if equipped) and transmission shift linkage ❏ Rotate tires (if required) 15,000 / 45,000 / 75,000 / 105,000 Miles Appendix-3 October, 2004 Noise, Vibration, and Harshness Glove Compartment EVERY 5,000 (or 3,000) Miles NOTES Appendix-4 October, 2004 Noise, Vibration, and Harshness NVH DIAGNOSTIC GUIDE Dealer: _ Date: P.A Code: _ Order No Technician: Owner’s Name: Address: Phone No Home: Work: _ Vehicle Make: Model: _ Year: VIN: _ Mileage: Engine: Trans: Axle: OWNER’S DESCRIPTION OF COMPLAINT: Did Condition Exist When Vehicle Was New? Yes / No (circle one) How Did Condition Begin? Gradually Suddenly At What Mileage Did It Occur Or Begin Occurring? _ Which Driving Conditions Affect The Vehicle? Light Accel Closed Throttle Decel Brakes Applied/Released Medium Accel Coast (Float) Driving The Vehicle: Straight Heavy Accel Constant Speed Cornering Is Vibration Noticed? If So, Where: Seat Steering Wheel Instrument Panel Floor Body Panels Ft/Rr of Vehicle Is There Sound Or Sensation Of Sound? Yes / No (circle one) If So, Describe The Sound: Boom Hum Whining Growl Other _ Drone Tip-In-Moan Squeak Rattle PREDRIVE CHECKS Tire Condition/Pressure: _ Vehicle Body Damage? Other: _ ROAD TEST: Vibration/Noise Occurs: Vehicle Speed Accel Vibration Frequency Hz/RPM Gear Range Decel/Coast _ Engine Speed _ RPM ENGINE RUN-UP TESTS Neutral Engine Run-Up (NERU) Yes / No Engine RPM Vibration/Frequency _ Hz/RPM Drive Engine Run-Up (DERU) Yes / No Engine RPM Vibration/Frequency _ Hz/RPM Drivetrain Run-Up (DTRU) Yes / No Engine RPM Vibration/Frequency _ Hz/RPM Indicate Suspected Area of Concern: Tire/Wheel/Brakes Engine/Accessory Rear Driveline/Axle Susp/Steering Right Body Front Left Other Equipment Used: Read Tachometer Electronic Noise Detector Tape Engine Tachometer Ultrasonic Lead Detector Other _ Noise, Vibration, and Harshness October, 2004 Appendix-5 WHEEL/TIRE/BRAKES CHECK: Balance Check Yes / No Maximum Runout Allowed: Wheel: Radial Lateral _ Tire: Radial Lateral _ Measured Runout: Tire/Wheel Radial: LF LR Lateral: LF LR Wheel Only Radial: LF LR Lateral: LF LR Brake Components: Excessive Rotor Runout? Yes / No RF RF RF RF RR _ RR _ RR _ RR _ SUSPENSION INSPECTION: Can Cause: Shimmy Clunk Squeak Harshness Suspension Bushings: Loose Worn Missing OK Front Upper Control Arm Stabilizer (sway bar) Rear Lower Control Arm Front Lower Control Arm Rear Upper Control Arm Rear Upper Control Arm Other Suspension/Steering Components: Ball Joints Shock Absorbers F/R Springs F/R Loose Worn Missing OK Idler Arm Center Link Tie Rod Ends/Sleeve Pitman Arm Steering Gear Steering Coupler DRIVESHAFT CONDITION: Noise Vibration Balance Weights Missing/Other Visual Defects? Yes / No Maximum Allowable Runout: Actual Runout: Two-Piece Driveshaft Runout: Middle Support Bearing: Front _ Middle _ Rear _ Front _ Rear _ Loose Damaged Worn Other Suspect Drivershaft Balanced? Yes / No Pinion Angle: Engine Height: Specification Actual Pinion Angle: Specification Actual Specification Actual Driveline Angle - Truck: ENGINE/ACCESSORY CHECK: Engine Mounts: OK Defective Grounded Visual Inspection / Comments: Electronic Noise Detection Results Comments: _ Air Intake Accessories Exhaust Engine Comments BODY (NOISE/RATTLE) Indicate Suspected Area of Concern: Doors Tests Used to Isolate NVH Concern: Vacuum/Leak Detector Electronic Noise Detector Windows Dash Panel Other _ Ultrasonic leak Detector Tracing Powder Other _ ROAD/ENGINE RUN-UP TESTS: Improved? Yes / No Vehicle Acceptable? Yes / No Comments: _ Appendix-6 October, 2004 Noise, Vibration, and Harshness FREQUENCY AND RPM CALCULATIONS TIRE AND WHEEL Vibration occurs at mph (km/h) Tire diameter Tire speed RPM and frequency from chart RPM Hz DRIVESHAFT Tire/wheel frequency x axle ratio = Hz Tire/wheel RPM x axle ratio = RPM ENGINE FREQUENCIES AND ASSOCIATED RPMS Engine RPM divided by 60 equals 1st order frequency 1st order RPM x = 2nd order RPM (normal for cylinder engines) Cylinders fired per engine revolutions Hz RPM 1st order Hz x = 2nd order Hz (normal for cylinder engines) Hz 1st order RPM x = 3rd order RPM (normal for cylinder engines) 1st order Hz x = 3rd order Hz (normal for cylinder engines) x = 4th order vibrations (normal for cylinder engines) x = 5th order, x = 6th order, etc Order of vibration x engine RPM equals cylinders fired per minute Order of vibration (2nd, 3rd, 4th etc.) x 1st order Hz equals RPM Hz ENGINE ACCESSORY FREQUENCIES AND RPMS Crankshaft pulley diameter divided by accessory pulley diameter = pulley size ratio Engine speed RPM x pulley ratio = accessory RPM Accessory pulley RPM divided by 60 = Hz Noise, Vibration, and Harshness October, 2004 Appendix-7 NOTES Appendix-8 October, 2004 Noise, Vibration, and Harshness DAY ONE – HOMEWORK Imagine yourself as the instructor for the NVH course None of your students have any experience with NVH How would you explain the concept of frequency to them? Be creative and use examples _ _ _ _ How does order of vibration relate to frequency? _ _ _ _ Why is proper sensor placement important when using the EVA? _ _ _ _ What is the function of the ChassisEar and how does it accomplish this function? _ _ _ _ Read Lesson Three: Diagnosis of NVH Concerns for tomorrow Noise, Vibration, and Harshness October, 2004 Appendix-9 NOTES Appendix-10 October, 2004 Noise, Vibration, and Harshness DAY TWO – HOMEWORK What are the three most important pieces of information you need to diagnose a vibration concern? _ _ _ _ How does the identification of a vibration frequency help in NVH diagnosis? _ _ _ _ Why is it important to understand the concept of noise transfer path in diagnosing a vehicle noise concern? _ _ _ _ What system(s) would you inspect if a customer is complaining of a harshness concern? _ _ _ _ _ What is the significance of the frequency calculations? _ _ _ _ Noise, Vibration, and Harshness October, 2004 Appendix-11 NOTES ... October, 2004 Noise, Vibration, and Harshness DAY ONE: INTRODUCTION TO NVH FUNDAMENTALS OF NVH Frequency ONE CYCLE SEC NVH0 02-A Frequency and Cycle Most vibrations consist of movements back and forth... examination and the ability to pass a hands-on post-test Noise, Vibration, and Harshness October, 2004 Intro-1 NOTES DAY ONE: INTRODUCTION TO NVH TECHNICIAN OBJECTIVES • Define vibration terminology and. .. Definition of Noise • Definition of Harshness October, 2004 1-1 DAY ONE: INTRODUCTION TO NVH WHAT IS NVH? The letters NVH stand for Noise, Vibration, and Harshness Any noise, vibration, or harshness