Julius Erving has been on championship teams before; two, in fact, both in the old American Basketball Association. He remembers the feeling. It was something special, he says, something he will carry with him the rest of his life.

Erving also remembers the disappointment and pain of coming so close to a National Basketball Association championship for so many years with the Philadelphia 76ers, and always coming up short.

That is all about to change.

The 76ers lead the Los Angeles Lakers, three games to none, in the best of-seven championship series. Game 4 will be played Tuesday night at the Forum (WDVM-TV-9 at 9).

The Lakers, in a state of shock after the way the 76ers have beaten them in the first three games, the last a 17-point loss here Sunday, may be without both Norm Nixon (shoulder separation, injured knee) and Bob McAdoo (thigh pull) Tuesday. Both are listed as questionable.

Lakers Coach Pat Riley definitely will be without $3,000. The NBA fined him that amount today for remarks he made about referee Darell Garretson following Game 2, in which the Lakers set a playoff record low by getting only five free throws (Story, Page D4).

As disoriented as the defending champions are, the 76ers are performing like a team that wants to be remembered as one of the best ever.

After having the best regular season record (65-17), they have breezed through the playoffs. A victory Tuesday will make them 12-1, a playoff record. Their only defeat was by the Milwaukee Bucks in the fourth game of the Eastern Conference final.

A Philadelphia victory also would result in the first four-game sweep in the championship series since the Golden State Warriors did it to the Washington Bullets in 1975.

"We're just waiting to bust loose," said Erving. "They (the Lakers) aren't going to come back. I don't think they're going to win, but they are going to come to play."

Erving's disappointments as a 76er started in the 1977 playoffs when, after winning the first two games against the Portland Trail Blazers in the final, the 76ers lost the next four games.

They lost to the Lakers in the final in six games in both 1980 and last season.

"Each time," said Erving, "it hurt a little more. But I've credited being denied before as necessary parts of my growth and my development as a person, emotionally and spiritually. It's almost been like a religious experience and, once it's attained, the first thing I'll do is give thanks.

"The main thing about winning the championship now isn't just winning it, but to keep the team together and try to win it again. We want this to promote togetherness and unity. There is a common bond of respect and admiration that you just can't share unless you've won a championship together. The bond you build with a group of guys who have gone all the way with you stays with all of you forever."

There is that certain something about Erving that makes people pull for him. Maybe it's his grace, or his graciousness. Whatever, it's there.

"In all of my 33 years," he said, "I've never blown my own horn, other people have done it for me. There must be something that's going on in my life, my makeup, my emotions, that makes people pull for me and that makes me feel good."

"Doc is special," Coach Billy Cunningham said of the only player still with the 76ers who was playing for them when Cunningham became coach six years ago. "I know it's important to every man on this team to win it for Julius."

Erving added that the 76ers are not complacent. "I think what is happening now hasn't ever happened before with the 76ers. Billy is driving us, not letting us let up. We have the determination to close this out Tuesday."

He then paused and looked around the 76ers' dressing room in the Forum. He looked at Bobby Jones, then at Moses Malone, two others who first played in the ABA.

"There's a lot of satisfaction having those two here," he said. "The old ABA days were the good old days and the ABA titles meant every bit as much as the title we're about to win. The NBA title wasn't available to me then, so the ABA title was the top."

Erving has been a scoring champion, a most valuable player in two leagues, and an all-star every year. He even was awarded an honorary doctorate in the performing arts from Temple University last week, making him a real Dr. Dr. J. He has the respect of his peers, his admirers, his followers and those who chronicle his exploits for a living.

"I don't need a championship to validate all of that," he said.

"Winning the championship isn't an end, or the culmination of a dream--it's only the beginning, because I'll continue to play. I have two years left on my contract, and I'm focused in on 1985 as when I retire. But I won't hang around that long if they don't want me."

He said it with a smile and everybody laughed.