Ford Motor Co., almost lost in the official anxiety over Chrysler's survival and Japan's import wave, is introducing a new 1981 subcompact that is critical to its recovery from its worst year since the end of World War II.

The first models of the 1981 Ford Escort and Mercury Lynx came off the production line at Ford's Wayne, Mich., assembly plant Monday, the advanced guard of what Ford hopes will be run of 485,000 cars this year. The new cars will also be produced at Ford's Metuchen, N.J., plant.

The Escort and Lynx are the only truly new additions to Ford's line this year and thus carry the burden of bringing would-be car buyers back into Ford dealer showrooms and producing a profit in the final three months of 1980.

Ford's loss during the second quarter was a staggering $468 million, and more red ink is expected in the third qurter, as it begins production of the fall line.

For the Escort and Lynx, the challenge is formidable. Even more than Chrysler's new products, the new Ford cars will be in head-to-head competition with the Japanese imports that dominated the subcompact market this year. They are larger than the subcompact Chevrolet Chevette and smaller than the Chevrolet Citation and Chrysler's highly publicized K cars, another new model this year.

The Escort and Lynx are powered by four-cylinder, front-wheel drive engines, a key factor in the popularity of imported subcompacts, and are expected to get about 30 miles per gallon in city driving and over 40 miles per gallon on the highway, Ford officials say. Ford has not announced prices for the new models, but they are almost certain to be cheaper than the Japanese and other competitive imports. The five best selling U.S. small cars are priced about 10 percent below the comparable best-selling imports.

Auto analysts are expecting the U.S. automakers to price the 1981 models about 6 percent higher than comparable 1980 cars on the average and the front-wheel-drive compacts and subcompacts -- the most popular American cars -- will carry the heftiest increases.

Prices of Chrysler's new front-wheel-drive K cars, the Dodge Arises and Plymouth Reliant, will begin at $6,065 and approach $7,000 for fully equipped station wagons, according to preliminary indications. According to Treasury Department analysts, Chrysler's strategy has been to price its K cars just below GM's competing X car models. GM's 1981 price decisions have not been disclosed.

Ford has recognized along with Chrysler, however, that quality is likely to be more important than price in diciding the popularity of its new cars. When Ford surveyed American buyers of Japanese-made cars to find out the most important factors in their choice of new cars, more than three out of four said quality of production, Ford officials say.

Like Chrysler, Ford has publicly embraced quality with a born-again fervor, and is willing to experiment to find formulas that work. Ford officials announced a new quality control program Monday for the Wayne, Mich. assembly plant, involving an unprecedented delegation of responsibilty to its hourly production line workers.

William E. Scollard, Ford vice president for body and assembly operations, said that 248 hourly workers have been designated "quality upgrade operators" and will be freed from customary assembly line work to aid suspervisors in preventing poor workmanship.

The newly recruited quality inspectors will make certain that trained operators are on duty at the start of each shift, serve as instructors for new employes, help straighten out tooling or material problems on the line and make sure these are enough parts at each station. Finally, the hourly employes will met regularly with plant management to discuss better production methods.

Scollard said the involvement of production workers in quality control is unprecedented at Ford, or at any other domestic automobile manufacturer, although General Motors Corp. officials might quarrel with him.

All of the American automakers have linked arms with the United Auto Workers union this year on the quality problem, recognizing the threat to the common financial survival. Ford chairman Philip Caldwell, speaking to the employes of a new Ford transaxle plant in Batavia, Ohio last month, said: The plain fact is that the auto industry and our nation as a whole can no longer afford the luxury of misunderstanding and contention. Meeting the challenges of inflation, trade imbalances, interest rates, dependence upon foreign energy resources and a range of other domestic concerns, will require the best efforts from all of us."