As the Montgomery County Council concluded about 20 hours of hearings yesterday on the proposed redevelopment of Silver Spring, County Executive Sidney Kramer's plan for a large-scale new commercial center appeared -- at least for the moment -- to be in trouble.

After listening to protests from hundreds of area residents and after intense questioning of Kramer's staff, council members served notice that they planned to question fundamental aspects and many of the statistics that make up Kramer's ambitious vision for large-scale development of downtown Silver Spring.

Five of the seven council members expressed in varying tones their sympathy with Silver Spring residents who say Kramer's plan will allow development so massive that it will obliterate the old downtown and the added traffic in their neighborhoods will result in gridlock.

The intense debate over Silver Spring is regarded not only as crucial to the future pattern of development for much of the lower county, which is becoming increasingly urban, but also as a volatile political issue that could affect the future of Kramer and the council. Council action on the plan is scheduled for Oct. 13.

Kramer, a skilled politician who has yet to lose a major battle with the council, will return from vacation Monday and will once again encounter the warfare between a well-organized citizenry and a potent development commmunity.

Kramer advocates relaxing development controls to allow the addition of 13,500 jobs for downtown Silver Spring.

The current limit for new jobs in Silver Spring is 4,700. An estimated 25,000 people now work in the downtown and 7,500 more will be employed in already approved buildings.

Kramer will need four council votes to win approval for his plan. No council members are saying how they will vote, but early nose-counters for the executive come up with only three tentative votes: Council President Rose Crenca and members Michael L. Subin and William E. Hanna Jr.

Subin, generally Kramer's strongest ally on the council and one who is often sympathetic to development projects, had been leaning toward approval of all 13,500 jobs. But testimony from this week's public hearings -- in particular concerns expressed by Planning Board Chairman Norman Christeller -- has, in Subin's words, thrown him "off balance."

Crenca, widely regarded as an able leader, is generally seen as the key. A Silver Spring resident with strong roots in the civic movement, Crenca has said she would like to see downtown revitalization, but whether she will support development on the scale suggested by Kramer is not certain.

Crenca was singled out last night when nearly 900 Silver Spring residents -- a crowd clearly opposed to Kramer's plans -- packed the auditorium of the old Northwood High School.

"Mrs. Crenca, you are the most important. You live in Silver Spring . . . you have a history as a civic activist. We are looking to you for leadership," said Pat Singer, president of the Silver Spring-Takoma Traffic Coalition. "Will you stand with us now, when the stakes are as high as they've ever been, or not?"

Virtually everyone in the room stood, and there was sustained applause.

This council, in contrast to its predecessor, is inclined toward compromise with the executive. Kramer, however, has presented the revitalization of Silver Spring to the council as a virtual do-or-die proposition. He has said that a controversial project by developer Lloyd S. Moore to build a regional shopping mall and office complex at Georgia Avenue and Colesville Road is the "window of opportunity" to redevelop the downtown.

Opposition to Moore's project has formed around concerns about the traffic it will generate, and plans to demolish what some consider architecturally significant Art Deco-style buildings.

Moore's project as well as others pending cannot proceed because of what Planning and Policy Director Meg Riesett called a "conflict in public policies."

County plans for downtown Silver Spring called for high-density mixed-use projects near the Metro station, and the land has been zoned accordingly, said Riesett. But the conflict arises, she said, because of the 13-year-old county law that prevents the approval of any development unless there are adequate public facilities to support it.

Kramer's plan for increased development is based on an assumption that more people will use mass transit, thus relieving road capacity and opening the way for further development.

John J. Delaney, a lawyer with Linowes & Blocher who represents Moore, phrased the question of traffic versus development more bluntly. He contended in his testimony that the revitalization of Silver Spring is being held hostage to "the unfettered right of citizens to commute to and from work in single occupant autos during peak hours . . . . "

Traffic should be a consideration, he said, but it should not be the preeminent policy, taking priority over jobs, housing and the eradication of social and physical decay. Delaney said the county doesn't need a job ceiling to control growth because it already has the power through planning and zoning laws.

Roger W. Titus, attorney for the traffic coalition that opposes Kramer's plans, contended that the county overzoned the land and now realizes that the infrastructure of roads cannot support it. He suggested that the county downzone the land.

He said there is a serious legal problem with the county's continued use of the adequate public facilities ordinance because of a recent Supreme Court decision granting financial compensation to developers denied use of their land by government action.