GM Ends Silverado 1500 at Oshawa in November, Boosts HD Output

GM will stop building the Chevrolet Silverado 1500 at Oshawa Assembly in November 2026 and put that capacity into more Silverado HD output, then retool the Ontario plant for GMC Sierra HD “by 2028,” GM spokesperson Jennifer Wright confirmed to The Globe and Mail. Employment at the plant is expected to stay the same. If you’re shopping a 1500, nothing on the lot changes today; Fort Wayne already raised light-duty output. If you’re waiting on a 2027 HD diesel, GM is putting more plant behind it.

Wright declined to say when Sierra HD production starts. GM does not disclose plant volumes. Unifor Local 222 president Jeff Gray told the Globe he expects Sierra HD to roll at Oshawa by late 2028; that is the union’s timeline, not a GM start date.

Sources

• The Globe and Mail (Eric Atkins) (published October 6, 2026, 19:50 UTC / ~12:50 PM PT): Jennifer Wright on-record — Silverado 1500 ends at Oshawa in November; HD volume up; Sierra HD retool “by 2028”; employment unchanged; GM declines Sierra HD start date and volume disclosure; AutoForecast Solutions (Sam Fiorani) plant forecast; Unifor Local 222 (Jeff Gray) late-2028 Sierra HD expectation and trade-dispute framing
• GM Authority (Jonathan Lopez) (October 7, 2026): same Globe confirmation; Fort Wayne / Silao continuity for next-gen Silverado 1500; CA$144 million Unifor-linked Sierra HD investment note; third-shift cut context
• Reuters (Wa Lone) (January 29, 2026): background on the Oshawa third-shift cut, roughly 500 direct GM jobs, plant returning to two shifts

No separate public GM Canada / news.gm.com statement for the November cutoff was located at write time. The on-record confirmation is Wright to The Globe and Mail.

TruckDaily take

Who this is for. Shoppers tracking 2027 Silverado HD / Sierra HD diesel builds, especially anyone watching November production of the new 8.3L Duramax, who want plant capacity facts without inventory panic. Start with our 2027 Silverado HD pricing and 2027 Sierra HD pricing posts for the MSRP and $11,400 diesel option dollars.

Who should skip. Skip treating this as a U.S. Silverado 1500 shortage story. We are not claiming any cab or trim was Oshawa-only, and we are not predicting U.S. inventory gaps. Skip reading Unifor’s trade-dispute framing as GM’s stated reason; attribute it, don’t adopt it. Skip waiting for a GM Sierra HD start date that Wright would not give.

What we’d watch. If you’re buying a 1500 now, shop the truck on the lot and use our 2027 Silverado 1500 pricing guide. Fort Wayne continuity is the shopper fact that matters. If you’re ordering a 2027 HD with the 8.3L, treat the Oshawa HD boost as more plant behind the same November production window already tied to those pricing posts, not a promise of discounts or delivery dates.

What GM confirmed

Analyst forecast (not GM figures)

AutoForecast Solutions vice-president Sam Fiorani, cited by the Globe, puts Oshawa at about 114,000 trucks in calendar year 2026, nearly evenly split between Silverado 1500 and Silverado HD. He also forecasts about 40,000 Sierra HD units in the first year of production at the plant. Those are analyst estimates. Wright said GM does not disclose volumes; do not treat Fiorani’s numbers as company guidance.

What it means for 1500 shoppers

Light-duty Silverado supply does not end with Oshawa. The Globe notes GM previously raised Silverado 1500 output at Fort Wayne, Indiana, and GM Authority’s rundown of the same confirmation points to Fort Wayne and Silao, Mexico, continuing on the next-generation light-duty program. We are not mapping which cabs or trims leave Oshawa versus Fort Wayne; that detail was not published in these stories.

Background only: in late January 2026, GM cut Oshawa’s third shift and about 500 direct jobs while the plant returned to two shifts, per Reuters. Unifor has framed light-duty moves toward Fort Wayne as tied to U.S.–Canada trade disputes. That is the union’s position as reported; GM’s on-record message for this November cutoff is the HD boost and unchanged employment.

What it means for HD shoppers

Oshawa already builds Silverado HD alongside the 1500. Losing the light-duty line frees capacity for more HD builds at the same plant where 2027 Silverado HD production (including the new 8.3L L6P Duramax) is scheduled to start in November, per the production window we flagged in our HD pricing posts today. That is a capacity story, not a promise that your order ships sooner or that dealers will discount.

Sierra HD arriving at Oshawa is real investment talk. GM Authority cites a CA$144 million Unifor-linked commitment to prepare the plant for next-gen Sierra HD, but Wright would not pin a start month. Gray’s “late 2028” line is the clearest public union expectation in the Globe piece.

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