Firestone Tire & Rubber Co. officials knew of major failure problems with their "500" steel-belted radial tires as early as November 1972, according to documents released yesterday by the National Highway Traffic Safety Administration.
In a memorandum to the then-vice president for tire production, Marlo Di Dederico, on Nov. 2, 1972, Firestone's director of tire development, Thomas Robertson, warned thet problems with the steel-belted tires were so bad that "we are in danger of being cut off by Chevrolet because of separation failures."
Firestone, which recently negotiated the largest product recall in government history, maintained throughout the controversy over the "500" safety problems that it had no indication that there were any problems with the tires before the federal government issued its own findings early this year.
Firestone would not comment on the contents of the documents released yesterday. "We do not think any purpose is served by post-mortem discussion and dissection of isolated documents," a company spokesman said.
After concluding in July that the tire has a "safety-related defect" causing a massive number of failures and dozens of subsequent deaths and injuries, NHTSA asked Firestone to recall the estimated 15 million "500s" still on the road.
But the company fought the government recall efforts. Federal investigators went to court to obtain company data. An agreement under which Firestone said it would recall about 7.5 million tires and replace them free of charge, was reached last month.
The Firestone spokesman said yesterday that "We are proceeding with the recall and have already recalled more than 750,000 tires. We are replacing thousands more every week. We are living up to the terms of the final agreement.
After the agreement, however, the company fought efforts by NHSTA to make the record of the case public.
Yesterday however, after lengthy negotiations with Firestone attorneys, the government made public hundreds of internal company documents that show that high company officials did have considerable knowledge of problems with the itre long before the government and consumer groups began raising safety questions.
According to documents released yesterday, Di Federico, who has since become company president, and other high-ranking Firestone officials not only knew there were problems, but also were involved in trying to solve them before the condition worsened.
At no time, however, did the company warn the general public of the problems, which led to one out of every six tires sold being returned by consumers.
In fact, the company fought a government ordered recall in 1974, going to court and succeeding in limiting the recall to one batch of 400,000 made at one factory. The company claimed that, although the tires failed federal safety tests, the problems could be traced to a "bad batch" from only that plant.
Last month NHTSA Administrator Joan Claybrook announced, moments after the final recall agreement with Firestone was signed, that she would seek to hit Firestone with the maximum $800,000 fine because of the circumstances of that 1974 recall.
Claybrook said that, although the company contended that the problem was a limited one, it actually knew there were problems with all of the 500s. Technically, she pointed out, the company was guilty of putting tires on the road that did not meet federal safety standards. At the time, however, Claybrook did not release the documentation of Firestone's prior knowledge.
Further, although Firestone officials had testified before congressional hearings, conducted by Rep. John E. Moss' House Commerce oversight subcomittee, that they had no reason to believe that the failure rate of the 500 was abnormally hgih, new documents released yesterday conrradict that stand.
A January 1976 document reveals, for example, that the return rate of Firestone 500s was running as high as 20 to 25 percent.
Another document, dated Sept. 16, 1975, reveals that the company had also pinpointed much of the problem as failure of th adhesion holding the steel belts to the tire carcass.
"A hypothesis has been developed," wrote Firestone official P. F. Murray in a development report that goes to top management, "to expalin the accelerated degradation which prompted these investigations and some preliminary extrapolations made to explain certain modes of longerterm but yet premature tread-ply failures resulting from adhesion losses."
The highly technical memorandum placed at least some of the tire failure blame on the simultaneous corrosion of zinc and copper in the steel tire cords, but acknowledge that the problems were not yet solved.