For 1990-2009 cars

# Info - Vibration Analysis Worksheet

Subject: | Vibration Analysis Worksheet

Models: | 2007 and Prior Passenger Cars and Trucks

| 2003-2007 HUMMER H2

| 2006-2007 HUMMER H3

| 2006-2007 Saab 9-7X

This bulletin is being revised to add models and model years. Please discard Corporate Bulletin Number 03-00-91-001B (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
To: Dealer: Fax Number: VIN__ __ __ __ __ __ __ __ __ __ __ __ __ __ __ __ __ Procedure Performed By:

Date:

Model:

Year: Gear Ratio:

Odometer:

VIN __ __ __ __ __ __ __ __ __ __ __ __ __ __ __ __ __

TAC Case #, if applicable:

#### Conditions During Road Test Procedures

As 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 Readings

Refer 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:__________ HZ:__________ Gs:__________

2nd Line MPH:__________ 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):

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)

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)

Flange, right rear:__________ Hub, right front:__________

Flange, left rear:__________ Hub, left front:__________

Wheel stud runouts (max. 0.008 in)

Flange, right rear:__________ Hub, right front:__________

Flange, left rear:__________ Hub, left front:__________