Bulletin No.:

Service Bulletin

Date:

09-04-20-001H
August, 2023

INFORMATION
Subject:

Front Tire Chatter/Noise vs. Rear Differential Chatter

Models:

2006-2024 Chevrolet Corvette
2016-2024 Chevrolet Camaro

Attention: This bulletin also applies to any of the above models that may be Export from North
America vehicles.
This bulletin has been revised to add the 2023-2024 Model Years and the Important statement
at beginning of bulletin. Please discard Corporate Bulletin Number 09-04-20-001G.

Important: This technical service bulletin (TSB) can
only be completed by certified repair facilities who have
met all specific training, tool and equipment
requirements pertaining to the vehicle Brand and Model
serviced. Repairs must be performed by a technician
who has successfully completed the required training.
The purpose of this bulletin is to address a chatter
noise during low-speed tight turn conditions (i.e.
parking lot, driveway, etc.) primarily during cooler
ambient temperatures. The condition can be
experienced in all directions: right, left, forward,
reverse. The condition typically reduces or diminishes
when the vehicle warms up, but may be worse when
the pavement is wet.
Note: For the 2011-2013 model year, the Goodyear F1
tire, available on Corvette Grand Sports and Z06
models, has a significant tread design change. This
new design is more susceptible to tire chatter or hop
than the previous design.
This condition may be caused by two potential sources
of chatter:
• Front tire hop
• Rear differential chatter/noise
The following subjective evaluation will help identify the
correct source of the suspect noise.

Evaluation
Test Conditions/Location
• Vehicle condition: Condition typically occurs
following an extensive ambient soak of the
vehicle. A vehicle soak of at least eight hours
during cool outside ambient temperatures is
required prior to evaluation.
• Road surface: Clean (e.g. limited gravel), dry
asphalt or concrete surface with sufficient space
to complete two to three full vehicle turns at first
gear idle speed.
Copyright 2023 General Motors LLC. All Rights Reserved.

Important: Limit the evaluation to four full vehicle
circles.
1. With the engine running and the vehicle at rest,
turn the steering wheel in the direction of the
intended turns until full steering lock is achieved.
Allow the steering wheel to come off of full lock
position slightly to prevent power steering system
damage.
A hand position at the bottom of the steering wheel
(6 o’clock) assists in the evaluation, but is not
required.
2. Engage the clutch in first gear (manual
transmission) or release the brake and place the
shifter in Drive (automatic transmission). The
objectionable noise should be quickly detected
once the vehicle has made one to two circles.
3. With the vehicle moving in a tight circle and the
objectionable noise present, move the steering
wheel in ¼ turn increments away from the full lock
position. A maximum of ½ to ¾ turn from full lock
should be sufficient to determine the source.
4. With a hand at the 6 o'clock position as a reference
indicating full lock, move the steering wheel to the
3 or 9 o'clock position and hold briefly to evaluate
(two to three seconds). Continue turning from the 3
or 9 o'clock position to the 12 o'clock position and
re-evaluate (two to three seconds). Repeat if
necessary for a maximum of four complete vehicle
circles.
For more information evaluating this condition, U.S.
dealers should refer to the May 2010 Emerging Issues,
Course Number 10210.05 — What's Hot: Cars:
Corvette Vibration and Noise During Parking Lot
Maneuvers (available at www.gmtraining.com).

Page 2

August, 2023

Diagnosis
•

Front Tire Hop: The objectionable noise will
reduce in severity or cease during the turning
sequence immediately when the steering wheel is
turned (¼ steering turn will typically dramatically
reduce front tire chatter). In colder ambient
temperatures (