RICHMOND, Va. --

JR Motorsports on Friday reached an agreement to part ways with competition director Tony Eury Sr., uncle of team co-owner Dale Earnhardt Jr.

Eury has led JRM's Nationwide effort for five seasons and has spent 28 years in NASCAR, winning 55 races in the Nationwide and Sprint Cup series as a crew chief. But

JRM hasn't won a Nationwide race since Sept. 4, 2010, with driver Jamie McMurray.

"I can't think of anyone who has impacted my career and development as a driver more than Tony Sr.," said Earnhardt, who had Eury Sr. as his crew chief early in his career. "I know my dad ultimately put me in the Nationwide Series car back in the '90s, but Tony Sr. was the one who convinced him to do it.

"He was with me through two Nationwide Series championships and five full seasons as a Cup driver. We won a lot of races together, and as much as he impacted my career as a race car driver, he means more to me on a personal level. He's done a lot for this organization, and I thank him for it."

Kelley Earnhardt Miller, the general manager of JRM, said the conversation with Eury Sr. when they agreed to part "was one of the most difficult I've ever been a part of."

"I believe Tony Sr.'s passion for the sport is exceeded only by his yearning to excel in it, and that itself became the issue that both he and I struggled with," said Miller, Dale Jr.'s sister. "At JR Motorsports we do this to win races and compete for championships, and lately we have not met that standard.

"Being the competitor that Tony Sr. is, I know that bothers him more than anyone."

Eury's son, Tony Jr., remains the crew chief for JRM's No. 7 entry driven by Danica Patrick.

"I want what's best for Dale Jr., Kelley, Tony Jr. and all those employees. I really do," Eury Sr. said in a statement. "We accomplished a lot in a short time, and nobody is prouder of that than I am.

"I'm not sure what's next for me, and I'm not sure I'm in a hurry to find out."