1. Martin Trapp, Ford Motor Company, 5-18-06
Squeak and Rattle 101
Martin Trapp
Ford Motor Company
NVH S&R Department
Martin Trapp, Ford Motor Company,

2. Martin Trapp, Ford Motor Company, 5-18-06
Objective : To assure that the vehicle exhibits robust S&R preventative strategies.
The most effective way to cut warranty costs and eliminate squeaks and rattles from a vehicle is to design component, subsystems, and systems that will resist the inputs and excitations of the road and powertrain. These designs need to be incorporated early enough in the vehicle line program in order to be both feasible and cost effective.
Martin Trapp, Ford Motor Company,

3. Or the Elimination of Squeak
Squeak, Squeak
Martin Trapp, Ford Motor Company,

4. Martin Trapp, Ford Motor Company, 5-18-06
S&R are subset of all customer Unexpected Noises (UN). These noises are generally random and transient (short time). They can be categorized by physical phenomena
Squeak: frictional stick/slip caused by rubbing contact of adjacent parts i.e., door vinyl trim squeaks against to sheet metal
Rattle: impact contact of adjacent parts i.e., glovebox latch rattles against striker
Buzz: noise radiated from part undergoing resonance vibration i.e., windshield molding buzzes
Martin Trapp, Ford Motor Company,

5. Causes of Squeak and Itch
Shear Movements as Small as 1mm Between Surfaces Can Generate Noise
Many Parts Can Move 5mm – 10mm (body twist)
Static Coefficient of Friction Creates a Storage/Release of Energy Event (single event, Single Stick Slip, SSS = tick)
Multiple Adjacent Storage/Release Events Cause Unacceptable Noise (multi event, Multiple Stick Slip,
MSS = squeak)
Without Shear there is no opportunity for noise
Majority of movement is between 0.5mm and 5mm
Gradual SRE does not cause noise
Martin Trapp, Ford Motor Company,

6. Martin Trapp, Ford Motor Company, 5-18-06

7. Examples for Friction Stick-Slip
Stradivari
Middle armrest
Objectionable Stick-Slip
Pleasant Stick-Slip
Martin Trapp, Ford Motor Company,

8. Martin Trapp, Ford Motor Company, 5-18-06
Methods of Evaluation
Road Testing (Proving Grounds or End-of-Line) With “Trained” Ears
4-Post Test Equipment (Fixed or Portable)
Component Lab Testing With Controlled Parameters
LET’S TAKE A LOOK AT THESE INDIVIDUALLY
Martin Trapp, Ford Motor Company,

9. Test methods – S&R (Proving Grounds)
Martin Trapp, Ford Motor Company,

10. What are we Listening for?
Characteristics:
Amplitude
Frequency
Continuity (continuous or intermittent)
Direction
Recognition – familiar sound?
Martin Trapp, Ford Motor Company,

11. Martin Trapp, Ford Motor Company, 5-18-06
S&R is rarely masked
Low amplitude - rarely masked out - heard through noise from wind, road, engine and exhaust
[dB]
Audible
Music
Road
Speech
S&R
[Hz]
Martin Trapp, Ford Motor Company,

12. Squeak and Rattle: Test Track Layout Rationale
The test tracks are designed to provide the desired input energy (frequency range and amplitude) to excite specific squeak & rattle concerns.
Interior squeaks & rattles
Body creak
Chassis clunk / pop / other noise (suspension noise)
Loose stock
The surface lengths are optimized to allow sufficient time for the track to excite concerns and for the driver to recognize and locate the source.
Martin Trapp, Ford Motor Company,

13. Squeak and Rattle: Generic Best Practice S&R Test Track Layout
Cobblestone
Washboard
Body Twist on Turn
Vienna Block
Rope
Speed
Transition
Raised
Vienna Block
Angle Iron
DPG RB / EB
Body Twist Straight
400’
See following slide for details.
Martin Trapp, Ford Motor Company,

14. Squeak and Rattle: Generic Best Practice S&R Test Track Layout
Martin Trapp, Ford Motor Company,

15. Squeak and Rattle: Environmental Four Poster
Martin Trapp, Ford Motor Company,

16. Squeak and Rattle Component Testing
Isolate the specific component
Evaluate under controlled conditions
Ease of Root Cause Analysis
Martin Trapp, Ford Motor Company,

17. Squeak and Rattle Testing
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18. Martin Trapp, Ford Motor Company, 5-18-06
Squeak and Rattle
Martin Trapp, Ford Motor Company,

19. Martin Trapp, Ford Motor Company, 5-18-06
Upfront Design Process
Objective : S&R Engineer reviews new product content descriptions and program timing dates to be used in the development of test plans and quality roadmaps.
Look For:
New product content in highly sensitive S&R subsystems (ie. seats, I/P, suspension, body structure, closures hardware).
Models, option content, and body styles offered.
Build timing (AA, CP, IB, etc.....)
Development milestones (Engineering sign-off, DVP&R requirements).
Replaced 1PP with IB in the Build timing tick point.
Martin Trapp, Ford Motor Company,

20. Martin Trapp, Ford Motor Company, 5-18-06
Subsystems that are not carry over should be checked for rattle. Prioritize based on engineering judgement of rattle risk.
Historic Areas of Concern: IP
Console
Seat
Door System (latches, surfaces,…)
Improved Through:
Increased Design Clearance
Strengthened Areas
Verification Testing of Alternatives
Martin Trapp, Ford Motor Company,

21. Martin Trapp, Ford Motor Company, 5-18-06
FRONT DOOR WIRING AND CABLES
Martin Trapp, Ford Motor Company,

22. Martin Trapp, Ford Motor Company, 5-18-06
RH SIDE OF IP, BEHIND GLOVE BOX.
Martin Trapp, Ford Motor Company,

23. Martin Trapp, Ford Motor Company, 5-18-06
Need flock tape. Interface between center console.
Martin Trapp, Ford Motor Company,

24. Martin Trapp, Ford Motor Company, 5-18-06
Foam block needed to be added to 6” behind DVD attachment bracket. Foam block is 60mmx44mm by 50mm
Martin Trapp, Ford Motor Company,

25. Martin Trapp, Ford Motor Company, 5-18-06
Door trim bezel switch wire needs to be wrapped in foam sleeve
Martin Trapp, Ford Motor Company,

26. Martin Trapp, Ford Motor Company, 5-18-06
Well Protected Wire Harness
Martin Trapp, Ford Motor Company,

27. Martin Trapp, Ford Motor Company, 5-18-06
Add Flock tape (or increase retention) to prevent vinyl to sheet metal squeak
Martin Trapp, Ford Motor Company,

28. Martin Trapp, Ford Motor Company, 5-18-06
Tools: Material Pair Testing
Martin Trapp, Ford Motor Company,

29. Hard Plastic Compatibility Matrix
Martin Trapp, Ford Motor Company,

30. Martin Trapp, Ford Motor Company, 5-18-06
End of Presentation
Martin Trapp, Ford Motor Company,

31. Martin Trapp, Ford Motor Company, 5-18-06
Enjoy the Conference
Martin Trapp, Ford Motor Company,

32. Martin Trapp, Ford Motor Company, 5-18-06
Questions?
“Ask a question and you’re a fool for a minute. Do not ask the question and you're a fool for the rest of your life.” (Chinese proverb)
Martin Trapp, Ford Motor Company,