NASCAR has suspended Denny Hamlin's crew chief and car chief for six races for a failed post-race inspection at Indianapolis Motor Speedway.
Darian Grubb and Wesley Sherrill are both suspended through the Sept. 6 race at Richmond.
They are not eligible to return until the opener for the Chase for the Sprint Cup championship, Sept. 14 at Chicago.
Grubb was also fined $125,000.
Hamlin and team owner Joe Gibbs were both also docked 75 points in the driver and owner standings.
Hamlin finished third on Sunday in the Brickyard 400 and his Toyota failed post-race inspection.
NASCAR said Tuesday it found issues with several of the covers in the rear firewall of the driver compartment.
Loose or missing covers could vent the driver compartment and create more downforce for the car.