United Auto Workers union members at Chrysler Corp. yesterday voted overwhelmingly in favor of a new contract that gives them an immediate pay raise -- their first in two years.

The vote was 20,696 to 5,817, said UAW Vice President Marc Stepp.

"We feel the workers made a very wise decision in ratifying this agreement," Stepp said. "The up-front money was the major factor in causing all our members to ratify . . . ."

UAW President Douglas A. Fraser had predicted the contract would be ratified "by a comfortable margin."

An earlier tentative contract with Chrysler's autoworkers in the United States was rejected by 70 percent of those voting because it didn't contain an immediate pay raise.

U.S. Chrysler workers gave up wage increases and cost-of-living protection in 1981 to keep the automaker from bankruptcy. Their last pay raise was in December, 1980.

The UAW says that, on average, the new contract will give workers an extra $2,270 in their paychecks over the next year, including an immediate raise averaging 75 cents an hour.

About 10,000 Chrysler Canada Ltd. autoworkers voted overwhelmingly last weekend to approve their tentative contract with Chrysler, ending a 37-day strike. The Canadian contract also included an immediate pay raise.