United Auto Workers members are scheduled to vote Sunday on a tentative four-year agreement reached with Navistar International last week.
About 1,500 workers in Illinois, Ohio, Georgia, Pennsylvania and Texas have been working under an extended contract since it expired in October. Union locals have scheduled informational meetings this week.
Navistar, the maker of trucks and engines, employs 13,000 workers. The company had proposed lowering costs by freezing pensions and adopting a 401(k) plan. The pension plan was saved under the agreement, a source said.
No additional details were released.