The AFL-CIO, despite earlier misgivings, is expected to give its qualified support to the SALT II pact, officials of the labor federation said yesterday.

Sources said AFL-CIO Secretary-Treasurer Lane Kirkland, who voiced strong objections to the way the arms limitation pact was shaping up earlier this year, is now rallying support on the federation's Executive Council for a "consensus' position in favor of the treaty.

This would enable the council to endorse the treaty, probably with conditions, at its midsummer meeting in Chicago Aug. 6-8.

Until recently, it appeared that the 14-million-member federation would sit out the SALT debate in the Senate, even though a number of major AFL-CIO affiliates, including the Communications Workers, Steelworkers, Food and Commercial Workers, Machinists, Clothing and Textile Workers and the State, county and Municipal Employes, had endorsed the treaty.

Sources said Kirkland's conditions include "clearing up some definitional problems, although none would be considered "killer amendments"" and a commitment from the administration to develop the MX land-based missile.

They said Salt II would be endorsed as a "vehicle for reaching SALT III where we could get some real controls on the number of nuclear warheads...some real progress toward nuclear disarmament."

When Kirkland denounced the pact last February during the council's winter meeting, he said it would lead to "the greatest buildup of strategic arms in the history of man" because it failed to limit warheads.

"Now it appears that the only way to get to SALT III, and some controls on warheads, is by way of SALT II," said a federation official familiar with Kirkland's views.

In addition to being the federation's main spokesman on arms control, Kirkland is its second-ranking official behind President George Meany, who is ill and not expected to attend the Chicago meeting. Meany did not join in Kirkland's earlier objections to SALT II.