DETROIT — General Motors union workers ratified a record deal with the United Auto Workers after a contentious final few days of voting, according to results posted Thursday morning by the union.

Much like the negotiations themselves, voting was not as smooth as many thought it would be. A majority of the Detroit automaker’s large assembly plants rejected the pact, however it wasn’t enough to offset support at smaller facilities and a handful of other assembly plants.

Ratification of the deal came under doubt Wednesday morning, after seven of GM’s 11 U.S. assembly plants rejected the pact. But a swing in voting results in favor of the deal, specifically at a SUV plant in Texas, gave the agreement a much needed lifeline.

According to the UAW’s vote tracker, the deal was supported by 54.7% of the nearly 36,000 autoworkers at GM who voted. The vote total was 19,683 in support versus 16,275 against — a margin of 3,409 votes.

Both the UAW and GM declined to comment on the results until they’ve been finalized.

Voting on similar contracts at Ford Motor and Chrysler-parent Stellantis is ongoing, with support of roughly 67% of unionized workers at each automaker who voted as of Thursday morning, according to the union. Barring any major shifts or swing in turnouts, those deals are likely to pass.

GM’s voting was closer, in part, due to the demographics of the company’s workforce. The automaker has the highest number of traditional workers on a percentage basis compared to its crosstown rivals. Such workers have voiced disapproval for the wage increases granted to them by the deals, compared to those offered to newer hires. They were also dissatisfied with pension contributions and retirement benefits.

For the union and UAW President Shawn Fain, the deals represent significant economic gains. They include 25% pay increases; a path to secure future jobs for union ranks such as battery plants; and a springboard for organizing efforts at other non-union automakers operating in the U.S. — a main goal of Fain moving forward.

For the companies as well as their investors, the contracts represent the top-end of forecasted increases in labor costs. While the automakers several times called foul on the union’s tactics, including six weeks of targeted strikes, they should be able to stomach the cost increases. That’s not to say they won’t be seeking offsets to the increases elsewhere in the forms of future investments, restructuring and other means.

Ford CFO John Lawler last month said the UAW deal, if ratified by members, would add $850 to $900 in costs per vehicle assembled. He said Ford will work to “find productivity and efficiencies and cost reductions throughout the company” to offset the additional costs and deliver on previously announced profitability targets.