Hamlin crew chief says he didn’t cheat
Grubb, who was joined on the sidelines for six weeks by No. 11 car chief Wesley Sherrill, also was fined $125,000 and placed on probation through the end of the year.
Speaking on Friday at Chicagoland for the first time since his return to the track, Grubb told a scrum of reporters that NASCAR's issue with the rear firewall block-off plates on Hamlin's third-place finishing Brickyard car was not the result of an attempt to circumvent the rules.
"It was a nut plate that is used as an aircraft fastener, and it didn't have enough torque on it and backed off and came loose," Grubb said. "It's something we've taken out of the cars and have never seen again and never seen before. It's a 27-cent part that came loose. It wasn't torqued correctly."
Loose or missing covers in the rear firewall of the driver compartment could vent the compartment and give a race car more downforce.
"It's not a gray area, it's not anything intentional, there's no real performance gain there," Grubb said. "Everybody in the garage has those same covers, and they came loose the week that they shouldn't have come loose."
Grubb, who won the 2011 Sprint Cup title with driver Tony Stewart at Stewart-Haas Racing before joining Hamlin's No. 11 Joe Gibbs Racing team in 2012, was non-committal on Friday about his future with JGR beyond 2014 — the final year of his contract.
"We're still working on a lot of things and concentrating on winning a championship for Joe Gibbs Racing in the FedEx Toyota right now," he said. Fox Sports