CHARLOTTE, N.C. -- It was a slow prerace Sunday at Darlington Raceway, and Hall of Fame crew chief Dale Inman was having a spirited debate with the father of Kyle and Kurt Busch in the Sprint Cup garage.
Tom Busch argued that Jimmie Johnson wouldn't be a five-time champion if it weren't for Chad Knaus, saying it was the crew chief who made the team and driver great.
It went back and forth for almost 10 minutes before ending with the conclusion that we'll never know for sure until Johnson and Knaus break up and one or both has success with somebody else.
I was reminded of this debate last week when word surfaced that Tiger Woods and longtime caddie Stevie Williams had severed ties. I was reminded that nothing, no matter how good it might seem, lasts forever.
Brett Favre and the Green Bay Packers.
Jennifer Aniston and Brad Pitt.
It happens, people. One day, it might happen to Johnson and Knaus, who enter Sunday's race at Indianapolis Motor Speedway with pit crew issues and fewer wins (one) at this point in the season than in all but one of their title runs.
It happened to Inman, who, after seven titles and 192 of Petty's then-193 wins, left four races into the 1981 season to be the crew chief for 1980 Cup champion Dale Earnhardt.
That didn't quite work out as planned. Earnhardt left in August after a change in team ownership, and Inman eventually was paired with Terry Labonte, winning the 1984 title to make him the only crew chief in NASCAR history to win a title with two drivers.
Petty, by the way, won only seven races the rest of his career and finished no higher than fourth in points.
Inman didn't openly discuss the split then and won't now, other than to say, "It certainly wasn't mine and Richard's relationship or the way we were getting along" that caused it.
It doesn't matter, although many will tell you it was because Inman was offered more money than any crew chief imagined at that time. But it shows that no relationship is safe, even when those in it are on top of their game.
Johnson and Knaus are at the top of their game. Despite the fact that only one win in the first 19 races has some calling them vulnerable, they are second in points and their overall numbers are as good as or better than ever.
That their relationship has survived this long puts them in rare territory. Their 10-year run is three years longer than the second-ranked pair of Denny Hamlin and Mike Ford.
We've seen four crew chief changes in the past few weeks, with drivers Greg Biffle, Juan Pablo Montoya, AJ Allmendinger and Jeff Burton. It's part of the what-have-you-done-for-me-lately society in which we live.
So what keeps Johnson and Knaus together? Success that breeds respect as much as anything. All of the above changes came from teams outside the Chase cutoff needing to shake things up. You don't make changes when you're on the best run in the history of the sport.
Or do you? Inman left Petty four weeks after winning a seventh Daytona 500 and ranked first in the standings. Ray Evernham left Jeff Gordon late in the 1999 season coming off consecutive titles because he was offered a chance of a lifetime to become an owner with Dodge.
This isn't to suggest that Johnson and Knaus are going to split before the end of the season. They won't. But what if their title run ends? Could Knaus move into another role at Hendrick Motorsports because he has proved all he can as a crew chief?
He is contractually tied to the organization through 2015, and he says he's mentally tied to the No. 48 team. Those close to the situation will tell you he has turned down lucrative offers to leave before.
But most never thought Woods and Williams would split before things went awry. Most never thought Inman and Petty would split after being together for 30 years.
You just never know what will tear a great tandem apart.
"It's hard," Evernham said. "It's like a marriage but a lot more pressure. With marriage, you get to do other things together. When you're doing the same thing with somebody time after time after time, people change. People get older, and sometimes they want to do things differently and the other doesn't.
"Or sometimes they just get tired of each other. It's a difficult relationship to maintain under pressure."
Had it not been for team owner Rick Hendrick, this magical combination might never have won the first title together. Remember, after missing out on the championship for the second straight year in 2005, Johnson and Knaus were on rocky terms before Hendrick sat them down for the famous "milk and cookies" speech to remind them of how childishly they were behaving.
It worked, and the two have been unstoppable since.
But are we seeing signs of the relationship becoming strained again? There have been several times this season that Johnson has questioned Knaus' calls, most recently over tire strategy at New Hampshire in the most recent race.
"I don't know where people have had this impression that it's all holding hands and singing 'Kumbaya' for the 48 team," Johnson told me in May after a series of late-race pit strategies went against the team.
Johnson also reached his tolerance level at New Hampshire with what was supposed to be his new-and-improved pit crew after yet another pit road mistake cost him valuable track position late in the race.
"We can't have these mistakes anymore," Johnson said of the NFL-type crew Knaus assembled to make the team stronger and deeper. "We are way too close to the Chase, and we need to be right."
We've heard frustration in Knaus' voice on the radio several times in the past few months, too. He once suggested that he didn't know how to make a late-race call on tires or gas.
Maybe this is no different from seemingly every other midseason swoon the 48 team has experienced. Maybe JJ and Knaus will win at Indianapolis for the fourth time in the past six years and their world will be right again.
As Inman pointed out, he and Petty didn't always agree. It just wasn't made public like it is today.
But ultimately, Inman and Petty split.
"They probably will think about it at some point," Inman said of Johnson and Knaus splitting. "But then they probably will think about how they're both on top of the world with sponsorship and finances and all the other stuff that has to come into consideration.
"I'm sure one thing that will keep them together is Mr. Hendrick. He ain't no dummy. He knows he's got a gold mine."
But if they did split, would they be as great apart as they are today?
"They would both do well, but not as well as they have done together," Evernham said. "That's what happens to great teams. They are still great people, but you are not going to do as well as a great team.
"Jeff and I both did well [after we split], but not as good as we did together. Dean Martin and Jerry Lewis and whoever, teams together are stronger than people alone."
That doesn't settle the debate between Inman and Busch. Or maybe it does. Maybe it tells us that no individual is greater than the team.
"Richard always jokes that he would have won 400 races if it hadn't been for me," Inman said with a laugh. "I always say the same thing back at him. But I once did an interview on what makes a good crew chief. I simplified it all the way down to it takes a good driver, or a great driver.
"I will stick to that."
And I'll stick to the theory that no good thing lasts forever.
David Newton covers NASCAR for ESPN.com. He can be reached at email@example.com.