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Symptoms - Vibration Diagnosis and Correction

Table 1: Vibration Symptoms that are Felt
Table 2: Vibration Symptoms that are Heard

Note: Perform the following steps in sequence BEFORE using these symptom tables.

Perform the Vibration Analysis - Road Testing table before using these symptom tables in order to duplicate and effectively diagnose the customer's concern.

Symptom Tables

Refer to a Vibration Analysis table as indicated in the following symptom tables, based on the most dominant characteristic of the customer's vibration concern, felt or heard, that is evident during the appropriate condition of the occurrence.

Vibration Symptoms that are Felt

Category

Description

Typical Frequency Range

Condition of Occurrence

Area of Focus

Shake

Can sometimes be seen or felt in the steering wheel, seat or console.

Related terminology: shimmy, wobble, waddle, shudder, hop

5-20 Hz

Vehicle Speed Sensitive

Still occurs during freewheel down in NEUTRAL

Go to Vibration Analysis - Tyre and Wheel

Vehicle Speed Sensitive

Affected by torque/load and/or steering input

Go to Vibration Analysis - Hub and/or Axle Input

Engine Speed Sensitive

Go to Vibration Analysis - Engine

Roughness

Similar to the feeling of holding a jigsaw.

20-50 Hz

Vehicle Speed Sensitive

Still occurs during freewheel down in NEUTRAL

Go to Vibration Analysis - Tyre and Wheel

Vehicle Speed Sensitive

Affected by torque/load and/or steering input

Go to Vibration Analysis - Hub and/or Axle Input

Engine Speed Sensitive

Go to Vibration Analysis - Engine

Buzz

Similar to the feeling of holding an electric razor.

May be felt in the hands through the steering wheel, in the feet through the floor, or in the seat of the pants.

50-100 Hz

Vehicle Speed Sensitive

Affected by torque/load and/or steering input

Go to Vibration Analysis - Hub and/or Axle Input

Engine Speed Sensitive

Go to Vibration Analysis - Engine

Tingling

May produce a "pins and needles" sensation or may put hands or feet "to sleep".

Highest vibration frequency range that can still be felt.

Greater than 100 Hz

Vehicle Speed Sensitive

Affected by torque/load and/or steering input

Go to Vibration Analysis - Hub and/or Axle Input

Engine Speed Sensitive

Go to Vibration Analysis - Engine

Vibration Symptoms that are Heard

Category

Description

Typical Frequency Range

Condition of Occurrence

Area of Focus

Boom

Usually heard as an interior noise similar to the noise of a bowling ball rolling down an alley, deep thunder, or a bass drum.

    • Related terminology--droning, growling, moaning, roaring, rumbling, humming
    • May not be accompanied by a perceptible vibration or roughness

20-60 Hz

Vehicle Speed Sensitive

Still occurs during freewheel down in NEUTRAL

Go to Vibration Analysis - Tyre and Wheel

Vehicle Speed Sensitive

Affected by torque/load and/or steering input

Go to Vibration Analysis - Hub and/or Axle Input

Moan or Drone

Similar to the sound of a bumblebee or blowing air across the top of a bottle.

    • Related terminology--humming, buzzing, resonance
    • May be accompanied by a perceptible vibration such as a buzz

60-120 Hz

Vehicle Speed Sensitive

Affected by torque/load and/or steering input

Go to Vibration Analysis - Hub and/or Axle Input

Engine Speed Sensitive

Go to Vibration Analysis - Engine

Howl

Similar to the sound of the wind howling.

120-300 Hz

Vehicle Speed Sensitive

Affected by torque/load and/or steering input

Go to Vibration Analysis - Hub and/or Axle Input

Engine Speed Sensitive

Go to Vibration Analysis - Engine

Whine

Similar to the sound of mosquitoes, turbine engines, or vacuum cleaners.

300-500 Hz

Vehicle Speed Sensitive

Affected by torque/load

Go to transmission diagnostic information

   


© Copyright Chevrolet. All rights reserved
   


© Copyright Chevrolet. All rights reserved