JGR's announcement of Grubb comes three days after Mike Ford was released from his crew chief duties with the team. Ford had served as Hamlin's crew chief since his rookie season in 2006. They made the Chase for the Sprint Cup championship in each of the past six seasons.
Hamlin finished the 2010 season second in points and scored a series-high eight wins. He had only one victory this year, placing ninth in the Chase.
Grubb guided Tony Stewart to his third championship in NASCAR's premier series this season. Stewart won five of the 10 Chase races to capture the title. Halfway through the Chase, Grubb was informed that he would not be back with Stewart-Haas Racing in 2012.
"I'm thrilled to join Joe Gibbs Racing," Grubb said in a team statement. "The chance to work with Denny is something I'm excited about. When you sit down with Joe and J.D. Gibbs, you can't help but be excited about this opportunity and the team aspects of JGR. There is no question about the level of support you get here, and I'm looking forward to working with everyone across the entire organization."
Grubb, who became a first-time championship-winning crew chief, had been with Stewart's No.14 Chevrolet team since the inception of SHR in 2009. He helped the team to 11 wins and 59 top-10 finishes over that time.
Prior to his role with Stewart's team, Grubb worked for Hendrick Motorsports from 2001-08. He served as interim crew chief for Jimmie Johnson during the first four races of the 2006 season, winning two of those races -- including the Daytona 500.
"Darian is a great addition to our organization and person to lead our No.11 FedEx team," team owner Joe Gibbs said. "Obviously, he has proven the ability to guide a team to a championship, and we are excited to have him working with Denny toward achieving that goal here at Joe Gibbs Racing."