DETROIT (AP) — In a tight vote, thousands of United Auto Workers members at General Motors are expected to finish casting ballots Thursday on a tentative contract agreement that could be a giant step toward ending a prolonged labor dispute with Detroit’s Big Three automakers.

The outcome of the GM vote is uncertain, despite the UAW’s celebrations of victories last month on many key demands that led to six weeks of targeted walkouts against GM, Ford and Stellantis, the maker of Jeep, Dodge and Ram vehicles. The union is expected to announce GM results Thursday.

The three contracts, if approved by 146,000 union members, would dramatically raise pay for autoworkers, with increases and cost-of-living adjustments that would translate into a 33% wage gain. Top assembly plant workers would earn roughly $42 per hour when the contracts expire in April of 2028.

Voting continues at Ford through early Saturday, where 66.1% of workers voted in favor so far with only a few large factories still counting. The contract was passing overwhelmingly at Stellantis, where voting continues until Tuesday. The union’s vote tracker on Wednesday also showed that 66.1% voted in favor with many large factories yet to finish casting ballots.

About 46,000 UAW members at GM were wrapping up voting. As of Wednesday, those for the agreement outnumbered those against it by only 2,500 votes. That total didn’t include the tally from a 2,400-worker assembly plant in Lansing, Michigan, where 61% of members cast ballots against the contract. The union local there didn’t release actual voting figures.

Of the four GM plants that went on strike, workers at only a large SUV plant in Arlington, Texas, approved the contract. Workers in Wentzville, Missouri; Lansing Delta Township, Michigan; and Spring Hill, Tennessee, voted it down. Workers said that longtime employees at GM were unhappy that they didn’t get larger pay raises like newer workers, and they wanted a bigger pension increase.

Several smaller facilities were still voting, many of them parts warehouses or component factories where workers got big pay raises and were expected to approve the contract.

Keith Crowell, the local union president in Arlington, said the plant has a diverse group of workers from full- and part-time temporary hires to longtime assembly line employees. Full-time temporary workers liked the large raises they received and the chance to get top union pay, he said. But many longtime workers didn’t think immediate 11% pay raises under the deal were enough to make up for concessions granted to GM in 2008, he said.

That year, the union accepted lower pay for new hires and gave up cost of living adjustments and general annual pay raises to help the automakers out of dire financial problems during the Great Recession. Even so, GM and Stellantis, then known as Chrysler, went into government-funded bankruptcies.

“There was something in there for everybody, but everybody couldn’t get everything they wanted,” Crowell said. “At least we’re making a step in the right direction to recover from 2008.”

Citing the automakers’ strong profits, UAW President Shawn Fain has insisted it was well past time to make up for the 2008 concessions.

President Joe Biden hailed the resolution of the strike as an early victory for what Biden calls a worker-centered economy. But the success of the tentative contracts will ultimately hinge on the ability of automakers to keep generating profits as they shift toward electric vehicles in a competitive market.

Thousands of UAW members joined picket lines in targeted strikes starting Sept. 15 before the tentative deals were reached late last month. Rather than striking at one company, the union targeted individual plants at all three automakers. At its peak about 46,000 of the union’s 146,000 workers at the Detroit companies were walking picket lines.

In the deals with all three companies, longtime workers would get 25% general raises over the life of the contracts with 11% up front. Including cost of living adjustments, they’d get about 33%, the union said.

The contract took steps toward ending lower tiers of wages for newer hires, reducing the number of years it takes to reach top pay. Many newer hires wanted defined benefit pension plans instead of 401(k) retirement plans. But the companies agreed to contribute 10% per year into 401(k) plans instead.