A little-known clause in a federal regulation, a cautious Justice Department and aggressive delaying tactics by the Firestone Tire & Rubber Co. combined to handcuff the government in its recent negotiations over the recall of 13 million steel-belted radial tires.

Consumer advocates whose work led to the recall are bitter over the way it turned out. And Joan Claybrook, head of the National Highway Traffic Safety Administration (NHTSA) puts the blame on the company.

"Firestone's actions in this case gave American industry a black eye," she said after the recall agreement was signed on Nov. 29. "This is an example of a company that was knowledgeable of the problem for a long time and attempted to divert the agency form an investigation."

But is wasn't only Firestone that frustrated Claybrook and her crew.

A clause in the Motor Vehicle Safety Act Amendments of 1974 exempted tires from the regulation under which the government could order companies to purchase specific types of advertising to announce a recall.

That exemption, which NHTSA negotiators did not know about until after talks with Firestone and begun, virtually prevented the government form forcing Firestone to use massive television advertising to announce its recall.

"I can't believe that clause is in there," said one of the authors of the amendment. "It was not in the Senate version the bill, and it was slipped in when the House and conference committees met on it."

People who worked on the bill say they believe that tires were exempted from the advertising clause because the sale of every tire is supposed to be registered, thus making tire owners reachable by notification letter.

But, as the government learned from its talks with Firestone, the system of registration beyong company-owned stores is virtually in a shambles. Thirty percent of the owners of Firestone tires may never be notified officially that their tires are dangerous and will be replaced free.

Another snag in the government's fight to get Firestone to recall the estimated 13 million "500" steel-belted radial tires was the Justice Department's reluctance to take Firestone to court in the event that a deal was not reached.

NHTSA continually had threatened Firestone with the possibility of a government-mandated recall of tires if the tiremaker didn't come to terms on an adequate voluntary recall.

But, behind the scenes, NHTSA had its fingers crossed. Sources said Justice Department Civil Division head Barbara Babcock told NHTSA that such a mandatory action would result in a court fight, which, if held in federal court in Cleveland, might not turn out well for the government. Consequently, Babcock told NHTSA officials to work it out themselves.

The district court in Cleveland has earned a reputation for being tough on the federal government.

For its part, Firestone acted in such a manner as to delay the final agreement and dilute the impact of a recall that it estimated could cost the company up to $234 million.

That Firestone was not going to co-operate with NHTSA became apparent from the outset of the government's investigation into problems with the Firestone 500.

Only with the release by NHTSA last week of internal Firestone documents the company wanted to be kept under wraps did the public learn that Firestone executives were aware of serious problems with the 500 as early as 1972.

Some of the memos showed that in 1972-73 almost 30 percent of the Firestone 500s were being returned by customers.

But those memos did not come easily to the government. NHTSA had to go to federal court to get Firestone to give them up, and even then the company waited until the last minute to deliver the documents. A Firestone moving van dumped millions of documents at a Washington warehouse with only a couple of hours to spare on a court-ordered deadline, yet months after they were first requested.

And, up until the moment the documents were released, Firestone pleaded with the government to keep some of them secret, claiing that their release would reveal trade secrets.

"Firestone won a major victory in the 500 case," said Clarence Ditlow, director of the Center for Auto Safety, the consumer group largely responsible for alerting the government to problems with the 500.

"Through their stonewalling, delaying and deceiving tactics, Firestone won valuable time," Ditlow said, "especially when you consider that they manufactured some 24 million defective 500s."

Firstone spokesman Bernard Frazier denied that his company produced defective tries. "There is no evidence to substantiate the claim that we manufactured defective 500s," the said. "The NHTSA has not identified any specific defect in the tire."

Ditlow doesn's find the government blameless in what he calls the "Firestone Fiasco." "To this day," he said, "the public has no idea why NHTSA" FOUND ONLY THE TIRES MADE THRUGH MAY 1976 DEFECTIVE AND LET THE OTHERS GO UNRECALLED.

"THERE HAS BEEN A STONEWALL OF INFORMATION FORM NHTSA since the August hearings," Ditlow said, "How can the public have any confidence in this negotiated recall with such a lack of information?

"Firestone is the prime party to blame," Diwlot said. "Firestone, after all, made the defective tires and adopted the stalling tactics. But NHTSA and Joan Claybrook have to share the blame, because they went along. There is no question that, every time Firestone raised another objection, NHTSA gave in a little bit."

"Sure, this agreement should have and could have happened months ago," Claybrook said. "The ponderous decision-making process inside Firestone, and we presume this is one factor they took to deal with one issue after another." She added that Firestone took "three, four, five days to resolve every issue."

She said Firestone would often take aweek to answer even a simple question that had been posed by NHTSA to attorney Clark Clifford, who was hired by Firestone to conduct its negotiations.

Clifford, for his part, asked government negotiators to be patient with him since he was learning about the tire industry as he was working on the recall.

"In all my years of experience in dealing with the government and large corporations," Claybrook said, "Firestone is one of the most bureaucratic organizations I have run into."

Claybrook said Firestone's motivation for stalling was twofold: "They wanted to save as much money as possible, and they had a very serous concern about being defrauded by junk dealers bringing in old tires. They wanted to design some king of protection against that happening."

Still, Claybrook said, "This is an example of corporate values which give great weight to the saving of dollars with virtually no regard for the safety of the public."

Firestone's Frazier denied that the company deliberately stalled final ratification of the recall agreement.

"A recall of such magnitude is unprecedented," Frazier said. "The final agreement . . . covered a multitude of details that had not been fully discussed when the agreement in principle had been reached. We did not want to sign an imcomplete agreement and neither did NHTSA.

"As soon as it was complete to our mutual satisfaction, we both signed it. We had, however, begun replacing tires as soon as the agreement in principle was announced in October."

"This recall is by no means over," said consumer advocate Ralph Nader. "There is further analysis to be done on the newer 500s, and more will come out about this."

Nader wasn's too king to NHTSA and his old coworker Claybrook.

"There is nothing left for NHTSA but the further porosity of an unenforceable agreement with Firestone," Nader said.

Meanwhile, the recall proceeds. Firestone says it has replaced more than 750,000 tires, and is producing an extra 400,000 of its new 721 steel-belted radials each month to meet the demand.