Family diputes almost invariably are embarrassments for those involved and delicious scandals for just about everyone else. So when pro football's first family begins washing its dirty linen this week at U.S. District Court in Los Angeles, the nasty affair will be watched gleefully by football fans everywhere.

The parent-child unpleasantness matches the National Football League against its 1981 Super Bowl Champion offspring, the Oakland Raiders. More accurately, it's a fight between feisty Al Davis, Raider managing general partner, and just about everyone else in the NFL.

The main issue in the court fight is simple enough.

Davis wants to move his Raiders to the Los Angeles Coliseum, which was left without an NFL team last year when the Rams shuffled to surburban Anaheim. But the NFL constitution states that a team cannot move outside its own city without the consent of three-quarters of the other 27 team owners, and Davis doesn't have the votes.

The current case has its origins in 1978 when the Los Angeles Coliseum Commission filed suit against the NFL, saying that the league constitution restrained it from getting a replacement for the Rams who had just announced plans to move to Anaheim.

In January 1980 the Colisum disclosed that the Raiders would replace the Rams. But a month later, the NFL obtained a court order restraining the Raiders from moving. Nevertheless, on March 1 Davis signed an agreement to move to the Coliseum. Within a week, trucks began moving office furniture from Oakland to a newly rented Raider office Los Angeles.

But the league invoked the injunction and an Oakland sheriff halted the Raiders as they were moving vans bound for L.A.

Next, Davis took a more orthodox approach and turned to his fellow owners. But they voted unanimously against his planned move.

Finally, Davis an mid-1980 joined the Coliseum in its federal antitrust suit challenge to the NFL constitution, alleging that it was inhibiting competition.

Now, after months of public bombast and quiet behind-the-scenes efforts at settlement spurred by the presiding judge in the case, the two sides apparently have decided to leave their differences to a jury.

We don't think that the NFL is a religious brotherhood," says Raider attorney 'jospeh Alioto, a former mayor of San Franciso. "We think that the other owners are trying to restrain Davis' aggressiveness and hamstring him to an inferior stadium for the rest of his life while they move to new stadiums in the Meadowlands (as the Rams did),"

Jay Moyer, the NFL general counsel, says the league sees it this way: "It's aximatic that every club that joins the league must accept mutually made rules."

Then, reflecting the bitter feelings of the league toward Davis, Moyer adds: "The issue really is the morality of abandoning an area that has supported you for more than a decade, just to get richer."

The first order of business when the trail begins Monday will be choosing jurors. It's expected to be a laborious process, and it might take a week to find qualified persons to form the 10-person panel.

The reason: The affair has become such a cause celebre in the Los Angeles area that anybody who cares anything about pro football probably already has taken sides.

Since December, moreover, the Davis forces have been pumping the local press with stories, most of them aimed at Davis' longtime nemesis, NFL Commissioner Pete Rozelle. The most damning allegration is that Rozelle, acting with Ram owner Georgia Rosenbloom Frontiere, was somewhow involved in scalping tickets for the 1980 Super Bowl at the Los Angeles Coliseum.

To bolster their charges, the Davis forces have leaked selection portions of sealed testimony taken in preparation for Monday's trail. But the allegations, at least against Rozelle, so far are totally unsubstantiated.

Indeed, Judge Harry Pregerson, presiding U.S. District Court judge, has ruled that the plaintiffs cannot bring up the ticket-scalping allegations during the trial. The judge also has ruled that testimony concerning an alleged link between Davis and Allen Glick, a former Las Vegas hotel and casino owner with reported underworld ties, will not be allowed in the trail.

Earlier, the NFL tried to get the trial moved from Los Angles, arguing that the Davis publicity machine had so poisoned the atmosphere that there was no chance of a fair trial in that city. But Pregerson denied that motion.

During settlement talks, the NFL reportedly offered the nine-member Coliseum commission an expansion team to replace the Rams. But the commission has remained loyal to earlier agreements with Davis, insisting that any expansion team must include Davis an an owner.

The NFL countered that a new Los Angeles franchise must be open to bidding by any interested parties and that Davis could not get special treatment.

according to an NFL executive, some members of the commission want to dump Davis and settle, rather than face the costly fight. But Coliseum attorney Howard Daniels said that at a Wednesday Commission meeting, "There were no arguements, no discussion; the members said, 'Let's go ahead with the trail.'"

Public relations genious Rozelle, who for 21 years has managed to hold together the often fractious NFL owners, even manages to come up with a positive side to this family feud. "It's solidified the other 27, which can be helpful in other areas," he says.