Subject: | Vibration Analysis Worksheet |
Models: | 2008 and Prior GM Passenger Cars and Trucks (including Saturn) |
2008 and Prior HUMMER H2, H3 |
2005-2008 Saab 9-7X |
This bulletin is being revised to add models years. Please discard Corporate Bulletin Number 03-00-91-001C (Section 00 - General Information).
When diagnosing vibration concerns, use the following worksheet in conjunction with the appropriate Vibration Analysis-Road testing procedure in the Vibration Correction sub-section in SI. FILL OUT ONLY THE APPLICABLE PORTION OF THE WORKSHEET THAT APPLIES TO THE VIBRATION/NOISE.
Refer to the appropriate section of SI for specifications and repair procedures that are related to the vibration concern.
Vibration Analysis Worksheet | |
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To: Dealer: Fax Number:
VIN__ __ __ __ __ __ __ __ __ __ __ __ __ __ __ __ __
Procedure Performed By: Date: Model: Year: Gear Ratio: Odometer: VIN __ __ __ __ __ __ __ __ __ __ __ __ __ __ __ __ __ TAC Case #, if applicable: Conditions During Road Test ProceduresAs condition occurs: Engine RPM_____________ Vehicle Speed__________________ Vibration/Noise detected during the following road test procedures: Engine RPM_______________ Vehicle Speed_______________ Slow Acceleration Test: Yes__________ No__________ Neutral Coast-Down Test: Yes__________ No__________ Downshift Test: Yes__________ No__________ Neutral Run-Up Test: Yes__________ No__________ Brake Torque Test: Yes__________ No__________ Steering Input Test: Yes__________ No__________ Standing Start Acceleration (Launch Shudder) Test: Yes__________ No__________ Vibration/Noise Eliminated with TCC Commanded On: Yes__________ No__________ Vibration/Noise Eliminated with TCC Commanded Off: Yes__________ No__________ Vibration/Noise Duplicated on Hoist: Yes__________ No__________ When using the EVA, always take a snapshot. This will help determine which vibration shows up the most. Important: Vibrate software can also be used to assist in vibration diagnosis. Refer to Vibrate Software Description and Operation in SI. EVA ReadingsRefer to Electronic Vibration Analyzer (EVA) Description and Operation in SI for more detailed information. Important: As a reminder, place the EVA sensor where the vibration is mostly felt. Ensure the word "UP" on the sensor is physically facing up. The typical areas are the seat track, the steering column or the instrument panel. Locating the EVA sensor on additional area (i.e. the right fender, left fender, right quarter panel, left quarter panel, rear seat track, etc.) may also assist in determining the component causing the vibration/noise. The key is to look for the same Hz reading with the greatest amplitude G readings.
FILL OUT ONLY THE APPLICABLE PORTION OF THE WORKSHEET THAT APPLIES TO THE VIBRATION/NOISE:
Sensor at Steering Column: 1st Line MPH/KPH:__________ HZ:__________ Gs:__________ 2nd Line MPH/KPH:__________ HZ:__________ Gs:__________
Sensor at Roof: 1st Line MPH/KPH:__________ HZ:__________ Gs:__________ 2nd Line MPH/KPH:__________ HZ:__________ Gs:__________
Sensor at Passenger Seat Rail: 1st Line MPH/KPH:__________ HZ:__________ Gs:__________ 2nd Line MPH/KPH:__________ HZ:__________ Gs:__________
Sensor at Pinion Nose (Rear Wheel Drive): 1st Line MPH/KPH:__________ HZ:__________ Gs:__________ 2nd Line MPH/KPH:__________ HZ:__________ Gs:__________
Sensor at Pinion Nose Front Axle (Four Wheel Drive): 1st Line MPH/KPH:__________ HZ:__________ Gs:__________ 2nd Line MPH/KPH:__________ HZ:__________ Gs:__________
Sensor at Crossmember/Cradle (Front Wheel Drive): 1st Line MPH/KPH:__________ HZ:__________ Gs:__________ 2nd Line MPH/KPH:__________ HZ:__________ Gs:__________ Driveshaft Runout: Is round out within specification? Yes__________ No__________ Initial: Frt:__________ Center:__________ Rear:__________ Stub Shaft:__________ Current: Frt:__________ Center:__________ Rear:__________ Stub Shaft:__________ Pinion Flange Runout Reading:__________ Has a system balance been attempted: Yes__________ No__________ (If no, perform a System Balance) Were the drums removed to system balance? Yes__________ No__________ Initial: HZ__________ Gs__________ Current: HZ__________ Gs__________ Hose clamps added: Yes__________ No__________ Prop shaft indexed? Yes__________ No__________ If a System Balance has been attempted but the vibration is still present or system balance was not able to be achieved, check the ring gear backlash in eight different spots on the ring gear. Note that excessive ring gear runout may result in a first order tire speed or first order prop shaft speed concern. Backlash in eight equal spots on the ring gear (readings should not vary more than 0.002 in (0.050 mm)): 1__________ 2__________ 3__________ 4__________ 5__________ 6__________ 7__________ 8__________ Does the vehicle have any of the following components attached? Pinion damper: Yes__________ No__________ Pinion flange damper: Yes__________ No__________ Exhaust damper: Yes__________ No__________ Initial: Front angle:__________ Center Angle:__________ Rear Angle:__________ Current: Front angle:__________ Center Angle:__________ Rear Angle:__________ Were shims added to the following? Transmission/transfer case mount: Yes__________ No__________ Pinion nose (rear springs): Yes__________ No__________ Center Support Mount: Yes__________ No__________ Tire Size and Brand:_____________________________________ Wheel/Tire Runouts on vehicle (max. 0.050 in (1.27 mm)) Refer to Corporate Bulletin Number 00-03-10-006A for tire radial force variation. Right rear: Inner lateral:__________ Center radial:__________ Left rear: Inner lateral:__________ Center radial:__________ Right front: Inner lateral:__________ Center radial:__________ Left front: Inner lateral:__________ Center radial:__________ Mounting surface runouts (max. 0.005 in (0.127 mm)) Flange, right rear:__________ Hub, right front:__________ Flange, left rear:__________ Hub, left front:__________ Wheel stud runouts (max. 0.008 in (0.203 mm)) Flange, right rear:__________ Hub, right front:__________ Flange, left rear:__________ Hub, left front:__________ | |