CHARLOTTE, N.C. (AP) —Dale Earnhardt Jr. stayed loyal to his cousin and crew chief through last year's frustrating finish and this year's slumping start.

Amid wrong setups, misguided race strategies and pit-road problems, nothing seemed to tear the longtime duo apart.

Until team owner Rick Hendrick had seen enough.

Dale Earnhardt Jr. will have a new crew chief starting with this weekend's race at Dover because of a slump that has dragged deep into the season.

Tony Eury Jr. was removed as crew chief of Earnhardt's No. 88 team Thursday. The two are cousins and have worked together during Earnhardt's entire career.

Our performance hasn't been where it should be," said Rick Hendrick, owner of Hendrick Motorsports. "It's impossible to pin that on any one factor, but a change is the right decision at this point. We have a plan in place, and we're going to move forward with it,”

"We're going to put our full resources toward improving the situation and winning races," Hendrick said. "It's going to be a collective effort that includes all of our drivers, all of our crew chiefs and all of our engineers. Everyone in our company will be involved on some level."

Team manager Brian Whitesell will be the crew chief this weekend. Lance McGrew will take over next week on an interim basis as team owner Rick Hendrick decides on a long-term plan for NASCAR's most popular driver.

Whatever route Hendrick takes, he's giving Earnhardt the full-time use of Whitesell and Rex Stump, the lead chassis engineer.

Earnhardt Jr. and Eury Jr. left Dale Earnhardt Inc. last season to drive for Hendrick Motorsports. But despite driving for NASCAR's top team they have one win in 48 races with Hendrick and are 19th in points. They hit rock bottom with Monday's 40th-place finish at Lowe's Motor Speedway.

Earnhardt and Eury spent Tuesday and Wednesday testing on the road course at Virginia International Raceway. Hendrick told them he was splitting the pair upon their return.

Earnhardt and Eury are grandsons of Robert Gee, one of Hendrick's first employees. The two went through a rough patch that led to constant bickering at the end of the 2004 season when they raced for the championship at Dale Earnhardt Inc.

Earnhardt's stepmother, Teresa, separated them at the start of 2005, a move that led Earnhardt to finish a career-worst 19th in the standings. They were back together before the end of the season, but won just one race together in 2006 as Earnhardt's relationship with his stepmother rapidly deteriorated.

The next year, Earnhardt wrestled with the decision to leave DEI, then embarked on one of the most high-profile free agencies in NASCAR history. He settled on Hendrick Motorsports, and Eury went with him.

Although they opened their first season at Hendrick by winning the exhibition Budweiser Shootout and a Daytona 500 qualifying race, Earnhardt didn't win a points race until the 15th event of the year. That was at Michigan, his only victory all season.

Still, consistency put him at the top of the title contenders when the Chase for the championship began. But Eury and Earnhardt moved away from what got them into the Chase and finished last in the 12-driver field.

This year, Earnhardt opened with two pit-road mistakes in the Daytona 500 that put him in position to later trigger a nine-car accident. The pit-road errors have plagued him most of the season, but the poor showings have spilled onto the track as well.

Earnhardt has just three top-10 finishes this season and six finishes of 27th or worse. He's getting dangerously close to getting too far behind to rally for a spot in the Chase.

That's unacceptable for a driver who went to Hendrick to win the Cup title that has eluded him his entire career. His father, the late Dale Earnhardt, was a seven-time Cup champion before his death in an accident on the last lap of the 2001 Daytona 500.

Despite their shortcomings — two wins in the past 120 races — Earnhardt remained fiercely loyal to Eury and was pained when his rabid fans blamed the crew chief for their failures.

After Monday's rain-shortened race, Hendrick's commitment to the pair had clearly waned. Following months of steadfast support, he was noncommittal about Eury's future with Earnhardt.

"The guy that I feel bad for is Tony Jr. He gets criticized so badly," Earnhardt said in one of his early season defenses of Eury. "Everybody in this room, and some of you have criticized him, know how smart a guy he is and that he's a good mechanic and a solid crew chief. He just wants to do this for a living, just like I do. I'll take the fall. ... Every time I read in the paper that people are on his case I feel like I'm sending my brother to jail for a crime I committed."

Hendrick said shortly after that he was "100 percent" behind the pairing although promising to “make the call” if and when a change was needed. Thursday, Hendrick made the call.

"It seemed the harder we pushed, the more it unraveled," Hendrick told The Associated Press. "We need a new reason to get up and go to the track each morning, and the chemistry had broken down between them to the point where we just needed a fresh start."

Eury Jr. will move from the crew chief position into a key role with Hendrick Motorsports' research and development group. Eury posted one victory, one pole position, 19 top-10 finishes and 11 top-fives in 48 races with the No. 88 team.

In a statement released Thursday by Hendrick Motorsports, Eury was confirmed to have accepted the decision and acknowledged his move to another position within Hendrick’s organization.

"I have mixed feelings, and that's just natural," Eury said. "But I enjoy working at Hendrick Motorsports, and this is where I want to be. I'll do whatever I can to help all of our teams and try to be a part of another championship. I think a new challenge will be good."

"Tony and I talked through this last night," Hendrick said. "I want him here, he wants to be here, and he's going to be a big contributor to our future success. I have an unbelievable amount of respect for the job he's done and for the caliber of person that he is."

"Tony Jr. is a good crew chief," Earnhardt said during an appearance Thursday at Motor City Casino in Detroit. "We've had success, but this year, we aren't even mediocre. And the last couple weeks, we've arguably been one of the worst teams on the track. He's really, really talented, and I feel a lot of disappointment and failure for not being able to take advantage of that. Maybe the truth is that we just aren't meant to do it together. That's tough to admit, and even tougher to believe."