When producers and execs complain about dealing with SAG, their frustration often tends to focus on one person — Kent McCord.

On Monday night, McCord led an early and open revolt against SAG’s tentative deal with producers in a meeting of the Hollywood board, which voted 36-3 against the pact in a non-binding vote.

Though McCord’s never been SAG president, he’s the flashpoint for studio paranoia over the prospect of actors going on strike this summer. SAG-AFTRA contract negotiations concluded Thursday night on a 17-9 split vote to endorse a tentative three-year deal, raising the possibility that opponents may try to persuade union actors to vote down the deal.

For producers and execs, it’s McCord who sparks the biggest worries in his role as part of the Membership First faction of the guild’s elected leaders, a roster that includes such well-known actors as William Daniels, Valerie Harper, Diane Ladd, Esai Morales, Frances Fisher, Seymour Cassel and Elliott Gould.

Daniels, for example, doesn’t provoke the same reaction even though he led SAG as its president during a six-month commercials strike in 2000 and remains on the board. The genial Daniels is also just as well known for his work on “St. Elsewhere,” as the voice of the car in “Knight Rider” and as Dustin Hoffman’s father in “The Graduate.”

It’s McCord whom producers and execs were venting about during negotiations between the actors’ unions and the Alliance of Motion Picture & Television Producers.

Prior to the tentative agreement, there was concern that McCord’s side could campaign against ratification and torpedo the deal for not breaking through on boosting DVD residuals. The current contract runs out June 30; should SAG members vote the deal down, the outlook would be uncertain as to when the unions and AMPTP would start another round of talks; that would likely lead to a production speed-up, followed by a “de facto” strike as producers run out of time to start films that would wrap by June 30.

SAG prexy Melissa Gilbert and secretary treasurer James Cromwell said, “The group of members who oppose this contract are pursuing a political agenda — they are prepared to walk our membership off a cliff for purely political gain.”

The contract talks, launched Dec. 6, took place under a news blackout that precluded comment about the negotiations. McCord, Daniels, Fisher and Cassell are among the SAG reps on the negotiating team.

SAG watchers believe there are several answers as to why McCord has rubbed producers and execs the wrong way:

n He’s been at it for decades. The 62-year-old McCord is best known for his starring role as Officer Jim Reed on the hit series “Adam-12.” During the series run, he became active in SAG; he was named winner of the Ralph Morgan award for service to the guild in 1999. He served as treasurer from 2001 to 2003, then fell short in an attempt to unseat incumbent president Melissa Gilbert.

n He has an encyclopedic recall of SAG’s history and will often provide lengthy, detailed explanations to listeners.

n He brings a theatricality to confrontations, often wearing shaded glasses, and can often be strident. And he’s often not interested in compromising even if that means that SAG doesn’t present a united front. In short, that’s meant a lot of battling in and out of the SAG boardroom and at the negotiating table.

n He and his allies have racked up three clear victories in recent years by persuading SAG members to vote down initiatives proposed by SAG CEO Bob Pisano and president Gilbert — amending the master franchise agreement with agents to allow agents to own stakes in production companies and vice versa; merging SAG with AFTRA; and increasing SAG dues.

n He’s hostile to any perceived attack on SAG. For example, he refuses to work with any actor who’s “financial core,” a status that involves resigning from the guild while continuing to pay dues for the contract-related activities of SAG. Financial-core actors can’t vote in SAG elections; as in the case of Jon Voight, they aren’t allow to attend the SAG Awards despite being nominated for an award.

McCord has led a fairly straight-arrow life. He married high-school sweetheart Cynthia Doty in 1962, and they have three children. After meeting Ricky Nelson at a football game in 1961, he broke into the business on that most all-American of sitcoms, “The Adventures of Ozzie and Harriet,” where he was a regular for five seasons before hitting it big on “Dragnet” spinoff “Adam-12,” which ran in primetime from 1968 to 1975.

McCord’s done extensive charity work; his major passion outside SAG is driving race cars. He’s appeared in dozens of TV shows (“Galactica 1980,” “SeaQuest DSV,” “The Love Boat,” “MacGyver,” “Silk Stalkings”) and features (“Young Warriors,” “Airplane II: The Sequel,” “Predator 2”) along with commercials for products such as Hidden Valley Ranch salad dressing and Clorox.