Unions will take more delegates to the Democratic National Convention this month than they did in 1984 with their early endorsement of Walter Mondale - and it's largely because of Jesse Jackson, labor activists say.

Preliminary totals from the 90-union AFL-CIO and the independent National Education Association show a rec-ord 1,003 or 24 percent of the convention's 4,162 delegates coming from the ranks of the labor movement.In 1984, the two groups, which represent some 17 million workers, had 903 or 22.9 percent of the 3,933 delegates at the Democratic convention in San Francisco.

Of the 723 union members or officials on the AFL-CIO's roster of delegates for this year's convention, 56.4 percent are committed to Massachusetts Gov. Michael Dukakis, who has wrapped up the nomination, and 26.6 percent are pledged to Jackson.

Without Jackson's constant wooing of labor support through hundreds of appearances on picket lines and in local union halls and his populist appeal, political activists in the movement doubt they would be carrying as large a delegation to Atlanta.

"There is a genuine surprise within labor at how well we have done," said Allen Zack of the 1 million-member United Food and Commercial Workers Union. "It's the heavy influence of labor delegates in the Jackson camp. People really went out and scrambled to get on his slate."

Four years ago when its early endorsement of Mondale earned labor the tag "special interest" from Mondale's primary opponents, the AFL-CIO had a total of 642 delegates at the San Francisco convention.

Labor leaders looked upon Jackson and then-Sen. Gary Hart of Colorado as spoilers to Mondale's campaign. Hart tried to make amends in early 1987, before withdrawing his candidacy in the wake of an uproar over the weekend he spent with a Miami model.

Jackson began the reconciliation effort a year earlier at a private meeting in Chicago with the AFL-CIO's Committee on Political Education. He quietly raised $200,000 for a black voter registration drive in the South that was instrumental in returning the Senate to Democratic control that fall.

"I have a lot more respect for him than I did in 1984," said Loretta Bowen, political director for the Communications Workers of America. "He's no longer running against the party. As for the gut issues that affect organized labor, he articulated them better than any other candidate."

Joan Baggett, political director for the Bricklayer's Union, agreed that "having Jackson in the equation helped."

Because Jackson was able to stay in the race until the end, there was no repeat of the Mondale-Hart battle in 1986 where one was perceived as being pro-labor and the other anti-labor, she said.

"The assumption that the labor movement would come out on the short end of the stick, sans endorsement, was wrong all along," said Peter Laarman of the United Auto Workers. "The idea was to make it clear in a way that was not offensive or counterproductive but simply a reflection of reality - labor is a part of the process."

Laarman said the UAW will have 101 delegates at the Atlanta convention compared with 82 at San Francisco four years ago. Other large union delegations this year will be the NEA with 280 delegates, the American Federation of State County and Municipal Employees, with 159, and the American Federation of Teachers, with 152.

Despite the expectation of some minor fights over the party's platform, most union activists expect the convention and labor's role in it to be relatively quiet.