A Second Heavy-Duty Pickup Is Coming to a Plant Trump Wants to Punish
GM plans to build the GMC Sierra HD in Oshawa for $104 million — right as Trump threatens 50% tariffs on Canadian trucks starting 2027.
GM's Oshawa plant might stop being a one-truck town. The Chevrolet Silverado could soon get company on the line — the automaker's second heavy-duty pickup, the GMC Sierra HD. A tentative agreement with the Unifor union calls for a C$144 million investment — about $104 million — in production of the next-generation model.
This isn't a factory built from scratch. Back in 2023, GM already committed C$280 million to prepare Oshawa for the next generation of full-size gas-powered pickups. Today the plant builds the Chevrolet Silverado 1500 and Silverado HD, and GM itself describes Oshawa as capable of running light- and heavy-duty Silverados down the same line.
The new move expands that setup. If the deal goes through, the GMC Sierra HD joins the Chevrolet lineup. The C$144 million is roughly half of the previous modernization project — but this time the goal is more models coming off an already-upgraded line.
The timing is tense. The US still applies a 25% tariff on Canadian-built vehicles, though cars meeting CUSMA content rules get an exemption on their American-made parts. Trade talks between the two countries collapsed. And US President Donald Trump has said he intends to raise tariffs on Canadian cars, trucks and auto parts to 50% starting January 1, 2027.
Against that backdrop, adding the Sierra looks like more than routine reinvestment. It's a bet. GM is doubling down on Canadian-built heavy-duty trucks right as access to its biggest neighboring market could get dramatically more expensive.
But nothing is final yet. GM Canada officially confirms the Unifor deal is tentative and still needs approval from union members. It covers roughly 4,600 workers across plants in Oshawa, St. Catharines, Woodstock and Ingersoll. The vote runs August 29–30, with results expected once counting wraps up.
When bargaining began, only about 2,750 Unifor members worked at the Oshawa plant itself. For them, a second heavy-duty truck isn't just a line item — it's a shot at steadier work at the plant. The timeline for Sierra HD production and output volume, though, hasn't been revealed.
The next checkpoint isn't a pickup reveal — it's the ratification vote. Only after that will GM formally roll out the C$144 million investment program and set dates for building the new GMC Sierra HD in Oshawa.