Differentiating Chevy Chattering Problem

Owners of 2009-2019 Chevy Corvette vehicles may comment about a chattering noise during low-speed tight turn conditions primarily during cooler ambient temperatures. The condition can be experienced in all directions: right, left, forward and reverse. The condition typically reduces/diminishes when the vehicle warms up but may be worse when the pavement is wet.

This condition may be caused by either front tire hop or rear differential chatter/noise. The 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 should be clean (limited gravel), dry asphalt or concrete surface with sufficient space to complete two to three full vehicle turns at first gear idle speed.

With the engine running and the vehicle at rest, turn the steering wheel in the direction of the intended turns until a full steering lock is achieved. Allow the steering wheel to come off of the 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.

Engage the clutch in first gear (on manual transmission) re-release the brake and place the shifter in Drive (A/T). The objectional noise should be quickly detected once the vehicle has made one to two circles.

With the vehicle moving in a tight circle and the objectional 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.

With a hand at the six o’clock position as a reference indicating full lock, move the steering wheel to the three or nine o’clock position and hold briefly to evaluate (two to three seconds). Continue turning from the three or nine 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 turns.

FRONT TIRE HOP

The objectionable noise will reduce in severity or cease during the turning sequence immediately when the steering wheel is turned (1/4 steering turn will typically dramatically reduce front tire chatter). In colder ambient temperatures (20 degrees Fahrenheit), an additional ¼ turn (total of ¾ turn) may be necessary to sufficiently eliminate the front tire noise. If the diagnosis indicates the issue is tire hop, the condition is within the design criteria (normal condition) of the vehicle. Do not attempt repairs or change the differential fluid. Inform the driver that the noise is tire hop and is caused by the large amount of tire scrubbing across the pavement as the vehicle is turned.

REAR DIFFERENTIAL CHATTER

If at the ¼ and ½ turn stops, the objectional noise will not reduce in severity, the diagnosis indicates that the differential is the source of the noise. Note: Do not add a friction modifier in combination with DEXRON LS fluid. The limited slip and active handling features may be adversely affected.

Note: 2005-2008 models specify to drain and fill only with DEXRON LS Gear Oil (75W-90), P/N 88862624 (in Canada, use 88862625) for concerns of rear differential chatter. Note that the fluid used prior is a synthetic 75W-90 requiring four to six ounces of friction modifier. DEXRON LS contains a friction modifier that does not require an additional additive. 2009 and later models DEXRON LS Gear Oil 75W-90 P/N 88862624 (in Canada 88862625) was implemented to address rear differential chatter.

Note: for the 2011-2013 model year, the Goodyear F1 tire, available on Corvette Grans 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.