USING THE threat of bankruptcy like a club, the Chrysler Corporation has beaten the government into approving another $400 million in loan guarantees. In theory, the approval is still contingent on acceptance of extraordinary concessions by the United Auto Workers, the company's suppliers and its banks. But -- grudgingly, unhappily, against their better judgment -- everyone will once again go along. Nobody wants to be the holdout who destroys Chrysler and all those jobs. Lee Iacocca, the chairman of Chrysler, called it a "super deal."

Both the company and the union were moving fast to try to get the thing settled before Inauguration Day. They have succeeded -- assuming that all of those concessions come through. But the company is still running far greater losses than it, the government or anyone else expected. Last year's deficit came to an astounding $1.8 billion. The company obtained $800 million in federally guaranteed loans last year and, with the additional $400 million that it is now getting, it will set in the original legislation. Now is the time for both Congress and the Reagan administration to anticipate the possibility that Chrysler may be back for further guarantees later this year.

Congress set a good principle in the loan legislation when it declared that the successive federal guarantees were to be granted only as long as the company seemed to have a clear chance of survival. It is difficult to believe that the federal loan board, headed by the secretary of the Treasury, G. William Miller, can have arrived at that crucial finding last week without the deepest misgivings. Chrysler, its employees and its customers are entitled to a clear indication from both the White House and the Capitol regarding next steps. The basic decisions should not be left to the last minute to be settled in an atmosphere of crisis and hysteria.

Should the government continue to provide more loan guarantees after this latest round?To decide that one, ask yourself if the American economy would be stronger today if, for the past generation, the federal government had managed to keep Studebaker and Packard in the automobile business. They were good cars, and a lot of people regretted their disappearance at the time. But ask yourself if it would truly have been better for competition, for productivity and -- the thing that counts most -- for the welfare of working people in this country.

Unfortunately, but obviously, it would have been harmful. To have kept those companies going -- with federal money, repeated concessions from the unions and loans draining the suppliers that did business with them -- would have had widespread and unwholesome effects beyond calculation. The same thing will be true of Chrysler. The federal government has already gone as far as it can afford to go to rescue Chrysler -- and perhaps a little farther.