A General Motors plant once described as being on life support might not be out of the woods yet, but there's a new ray of light at Oshawa Assembly - Canada's oldest auto factory.

The plant's supply of models has dwindled in recent years, with only the Chevrolet Impala and aging Cadillac XTS sharing space with the soon-to-depart Buick Regal. For years, Oshawa's Consolidated Line handled final assembly of Chevrolet Equinox overflow models from GM's CAMI plant, but supply will dry up this summer as the next-generation model becomes a CAMI-only deal.

Enter a hazy GM promise to deliver pickups for final assembly. While GM hasn't confirmed that Chevrolet Silverado or GMC Sierra models are destined for Oshawa, at least one truck certainly is. The first truck shift hasn't yet begun, and already the local union is alerting workers to a second.

According to a Unifor Local 222 memo to its members, a second truck shift will begin in the second quarter of 2018. The memo, discovered by The Globe and Mail, details the addition of an extra 500 jobs to Oshawa to fill that shift, which comes shortly after the fourth-quarter start of the first truck line.

That first shift will employ 535 workers, made up mostly of soon-to-be-laid-off Consolidated Line workers (though regular Flex Line workers can apply). Unifor expects a retirement package to whittle down those 667 workers before the August layoffs.

A Reuters report published after last fall's GM Canada labor deal claims the overflow trucks will be full-size models coming out of GM's Fort Wayne, Indiana plant. The next-generation Silverado and Sierra bow for the 2019 model year, something Unifor hints at in its memo.

"All jobs are subject to change due to the truck being brand new," the memo states.

Meanwhile, Jennifer Wright, manager of corporate communications for GM Canada, tells TTAC that Regal production will end in June, leaving Oshawa with only two dedicated models. That doesn't put Oshawa on solid ground, though several company sources told us last November that more product is on the way.