Quieting Chevy 'Warble' Noise

This bulletin applies to 2014-2019 Chevy Corvette vehicles equipped with a 6.2L engine and 8L90 automatic transmission but excluding those equipped with RPO G96 electronic positraction limited slip. Some customers may complain about a “warble” noise from the rear of the vehicle when driving at an engine speed of about 1,500 RPM.

The noise may be more noticeable when traveling up a slight grade with little throttle input. This may be due to the bushing in the left side differential cover having too much clearance. The correction involves replacing the left side rear axle housing cover, using cover P/N 84705711 and nut P/N 11612295.