For nine years, Fairfax County School Superintendent S. John Davis successfully managed a delicate balancing act. He presided over painful decision about school closings, principal transfers, and a redrawing of school boundaries, yet he maintained the respect of the people most affected.

Then, two weeks ago, Davis' balancing act became unbalanced. Early on a Tuesday morning, two-thirds of the county's 7,000 teachers met and voted no confidence in the superintendent.

What angered the teachers was the county supervisors' failure to grant them the 9.4 percent pay raise they demanded. But their decision to blame Davis reflected a distinct shift in their perception of what a school superintendent should be.

Davis is one of three school superintendents in Northern Virginia suburbs to be censured by their teachers in recent weeks. All the disputes centered on salary issues.

As far as many Northern Virginia teachers are concerned, the school superintendent's job is no longer that of a mediator between competing forces: teachers, parents, county officials and taxpayers.

Now, in part because of a Virginia Supreme Court decision outlawing collective bargaining for school employees, the teachers have decided that it is up to school superintendents to fight their salary battle. There is no one else with clout to speak for them, the teachers contend.

"People are upset with him," said Bob Hicks, president of the Fairfax Education Association, whose members overwhelmingly voted no confidence in Davis. "They (teachers) feel that he (Davis) has lost touch with them. They perceive him as someone who is reluctant to come forth and voice their concerns.

"The superintendent should be speaking for the teachers," said Sam Sheller, a math and physics teacher at Langley High School. "He (Davis) really doesn't push hard enough on the teachers' behalf," Sheller said.

But Davis and other school officials disagree. "Jack is a very good spokesman for the teachers," said school board chairman Rodney F. Page. "If there's anybody around who can resolve the problems that they are having, it's Jack Davis. He shouldn't be made the villian in this."

"I'm concerned about the teachers," the 50-year-old Davis said. "The excellency (in the county school system) has been built by the dedication and efforts of the teachers," he said.

"They deserve a larger pay raise," Davis said. "But I don't control the purse strings."

The average teacher's salary in Fairfax is $18,500. FEA leaders say that salary is too low in a county where the average family income is $28,500.

"There is general teacher frustration," said Arlington School Superintendent Larry Cuban, who has been censured by his teachers because of a pay dispute. "An easy target are local superintendents. They are visible. They are handy to critisuze."

One Fairfax school official said the no-confidence vote was "a great personal blow" to Davis. "It hurt Jack very, very much," the official said.

Davis, who has been described as an "astute politician" because of his administrative style, is highly praised by other administrators throughout the state and nation, and is a top contender for the job of Virginia's statewide school superintendent.

Davis said he was told by county officials to keep the teachers' pay raise within President Carter's 7 percent guideline.

To comply, Davis proposed a 5.15 percent raise. When added to the already-mandated longevity increase that majority of the teachers receive annually, the raise would amount to about 7 percent in most cases.

FEA president Hicks, however, was not convinced by these arguments. Davis, he said, should have gone to the supervisors, who also received a no-confidence vote from the teachers, and demanded that the teachers be given more.

One long-time observer of the school system felt that such a course of action would have been an "empty show." Former school board chairman Mary Anne Lecos added that Davis "could have let the school board and supervisors be the fall guy, but he chose to bear the responsibility."

Lecos and some school officials said the backbone of the teachers' complaint is their loss of collective bargaining.

In 1977, the Virginia Supreme Court outlawed collective bargaining for public employes in the state.

Prior to that decision, county teachers, like other public employees, had a bargaining unit that negotiated salary increases and benefits with county officials.

Since that decision, public employes, including teachers, say they are losing benefits and higher pay increases because they have no one to speak for them.

"I've tried to keep pace with their concerns," Davis said. "I just haven't been successful."

As taxpayers have continued to demand that their elected officials tighten budgets, the competition for dollars has become increasingly fierce and teachers say they are bearing the brunt of the cuts.

When the Fairfax supervisors cut the county's proposed 1980 budget, the major victim was the school system, which lost $1.4 million of the $180.9 million it requested.

"The teachers obviously feel the pressure of the crisis," said Paul Salmon, executive secretary of the American Association of School Administrators. "Davis is caught just like every superintendent in the country."

In previous years, however, Davis managed to defuse potentially difficult situations without becoming an object of controversy himself. His secret was to pull other people into the process of making decisions, thus spreading around the responsibility and the credit for what happened in the schools.

Fairfax County, which has 130,000 students in its more than 164 schools, is the 12th largest school system in the nation and the largest in the state. Its students consistently score high on state and national tests.

Davis, who was named superintendent in 1970 after serving different administrative positions in the county since 1960, oversees a staff of 14,000 employes and a budget for next year of $372.4 million.

He is one of the top contenders for the job of state superintendent, which will become vacant July 1. Some officials said he is seriously thinking about accepting the job if it is offered.

"Jack works better in an atmosphere that is positive for what he is doing," said the school board chairman, Page, who added he would regret losing davis if he is offered the job and accepts.

Davis, who is married and has four children, earns $55,000 as school superintendent, $4,000 more than what he would be paid as state superintendent.

"It would be a challenge," Davis said of the state superintendent job. "Fairfax is a challenge, too," he added. CAPTION: Picture, S. JOHN DAVIS . . . "concerned about the teachers"