Lucille Dickess, the $16,180-a-year registrar of Yale University's geology department, never expected to find herself on a picket line shouting slogans against her employer of 16 years.

"You reach a point where you have to fight for what you're worth," said Dickess, 50, who once belonged to an antiunion committee. "You talk about the Mafia code of silence? Well, here, nobody ever talked about money and working conditions before . . . . But that's changed."

Yale, steeped in a 283-year tradition of scholarship and reason, has become the unlikely battleground in a bitter fight over what many experts see as a major labor and civil rights issue of the 1980s and beyond: "pay equity" or "comparable worth" for the lower-paid jobs traditionally filled by women.

A new and predominantly female union, representing 2,600 clerical and technical workers who are paid an average of $13,424, has been on strike against Yale since Sept. 26 because the two sides could not agree on their first contract.

The strike by the majority of Yale's secretaries, telephone operators, computer programmers and other clerical-technical workers -- supported by a sister blue-collar local -- has disrupted the placid academic atmosphere for Yale's 7,400 employes and 10,000 students.

Dining halls are closed. Libraries and other buildings shut early. About 400 of the more than 1,000 classes are being conducted off campus because faculty or students are often reluctant to cross picket lines.

Business and labor see the dispute as the first major private-sector collision over the assertion that employers systematically undervalue the skills, experience and job responsibilities of women.

The corollary assertion is that any imbalance between men's and women's pay can be remedied by objectively assigning an inherent value to a woman's job and then comparing it numerically with a man's job value to determine equity.

Comparable worth also has become a political issue. Democratic candidates Walter F. Mondale and Geraldine A. Ferraro have endorsed the idea to correct longstanding discrimination, while the Reagan administration has opposed it on grounds that pay levels should be determined by the marketplace, not by lawmakers, courts or unions.

"Yale has taken advantage of a societal tendency to underpay women and minorities, and we are asking them to change that," said John W. Wilhelm, a Yale graduate who is the organizer and chief negotiator for Local 34 of the Hotel Employes and Restaurant Employes Union (HERE).

But Yale officials and opponents of the pay equity concept say the union is falsely claiming sex and race discrimination as a cover for the real issue: an excessive demand for more money. They acknowledge that some inequities exist for Yale's female employes but attribute them to longstanding national economic and social priorities that Yale should not be expected to remedy single-handedly.

"We are firmly committed to nondiscrimination and affirmative action, and there has never been a single finding of employment discrimination at Yale," university Vice President Michael Finnerty said in an interview. "You have certain jobs that tended to be women's jobs because those are the jobs women ask for, not because we forced them into those jobs."

Nationally, women are paid on the average 62 cents to every dollar paid men, according to data gathered by the Bureau of Labor Statistics.

Low salaries for women's jobs began in an era when relatively few women worked outside the house, and the lower wages were often rationalized by the belief that most women were working for "pin money" to supplement a husband's salary.

Today, however, with a record 48 million women in the work place, at least 68 percent of them are self-supporting or have husbands who receive less than $10,000 a year, according to the BLS. Yet female breadwinners remain concentrated in the same clerical and service-industry jobs that some critics have called "occupational ghettos" of low pay and few benefits.

At Yale, the average pay for administrative assistants, a mostly female clerical category with a varied job description that runs more than 500 words, is $13,524. Yale's truck drivers, most of them men, require less education and training but get an average of $18,470, or 36 percent more.

The union labels this institutionalized sexism, while the university says truck drivers are paid more because that is the prevailing market rate and because they work 2.5 hours more a week, get less vacation and have more experience.

Yale contends that its wage offer is more than generous -- better than twice the current national average for raises. The university estimates that its wage offer would result in 24 percent raises over three years, compared with 49 percent if the union won its full demands.

Local 34 says that those figures are inflated and that the Yale offer totals 18 percent in three years compared with the union proposal of 29 percent, plus a partial cost-of-living raise.

In the most celebrated pay-equity case to date, a federal judge in 1983 ordered the state of Washington to revamp its pay system to end sex discrimination against 15,000 female employes. Those women stand to receive an estimated $500 million to $1 billion in raises and back pay determined partly by a new numerical job-rating system. The award, if upheld, would be the largest under the 1964 Civil Rights Act. The Reagan administration has joined the state in appealing the decision.

Minnesota is spending $22 million to begin implementing voluntarily a similar numerical job-rating system, and dozens of local and state governments are following suit, according to the National Committee on Pay Equity, a coalition of 200 women's, labor and civil rights groups.

But in the private sector, though an undetermined number of employers have restructured pay scales or begun studying the issue, none has been confronted with a strike over the issue, said Claudia Wayne, executive director of the coalition.

Interest has been heightened in the Yale battle because it is part of a recent nationwide effort by traditionally blue-collar unions -- such as HERE, the Teamsters and the United Auto Workers, among others -- to organize the growing white-collar sector that is overwhelmingly nonunion.

Fewer than 10 percent of office workers and 15 percent of female workers belong to unions, compared with 20 percent of the total work force.

AFL-CIO President Lane W. Kirkland, who came to a Yale strike rally here last Thursday, referred to the fact that no previous private-sector strikes have focused on pay equity.

"The issue at Yale is fairness" to women, he said, "and the results of this struggle will be felt far beyond Yale in work places throughout the land.