Rank-and-file members of the Teamsters union have overwhelmingly ratified a five-year deal with UPS, putting an end to the threat of a crippling strike.

The union said 86% of members had voted for the five-year contract, which will now be in effect retroactive to August 1. It was the largest margin in favor of a contract ever at the company, the Teamsters said. The deal was reached on July 25, a week before the union had been set to go on strike. The ratification process has taken the four weeks since then.

The deal had overwhelming support among union leadership, who voted 161-1 in favor of the deal. Teamsters President Sean O'Brien called it "the best contract in the history of UPS."

"This is the template for how workers should be paid and protected nationwide, and nonunion companies like Amazon better pay attention," said O'Brien in a statement on Tuesday.

But some groups of part-time UPS workers opposed the deal. The outcome of the vote had been uncertain because of opposition from those part-time workers, who were upset that they're still being paid less than full-time employees doing the same work.

Still, the union achieved many of its key negotiating goals, including across-the-board pay raises of $2.75 an hour that are retroactive to August 1 and total raises of at least $7.50 an hour, or more than $15,000 a year for full-time workers, during the life of the contract.

And some workers got even larger raises as the company agreed to eliminate a lower pay scale for many of the workers hired since 2018.

The company also agreed to address the complaints that 95,000 delivery vans in its US fleet do not have air conditioning. The union said that is more than an issue of comfort: It is a safety concern. Although UPS did not agree to retrofit the existing vans with air conditioning, it did agree to purchase only air-conditioned vans starting next year. And existing vans will be retrofitted with some changes to reduce the heat in the cargo area, where temperatures can pose the greatest threat.

This is a developing story. It will be updated.