Even as talks continue, the company is leery of settling the strike and saddling itself with costs that it will have to pay later.
Workers howled and GM received withering criticism from politicians and on social media about cutting off the benefits.
Minor issues largely are resolved, focus shifts to wages, use of temporary workers and other contentious issues.
The union wants a bigger share of GM’s more than US$30 billion in profits during the past five years.
Follows the full shutdown of vehicle production at the company’s Oshawa Assembly Plant.
On Friday, GM halted production on its flex line in Oshawa that produces the Chevrolet Impala and Cadillac XTS and employs about 650 workers.
In August, FBI raided the suburban Detroit home of UAW President Gary Jones as part of the widening federal investigation.
Unifor president Jerry Dias expects more cuts at Canadian operations.
Committees working on wages, health insurance costs, temporary workers and new work for plants slated to close.
Companies are looking to adjust production schedules to adapt to the disruption.
More than 49,000 United Auto Workers members have brought to a standstill more than 50 factories and parts warehouses.
33 manufacturing plants down in nine states across the US, plus 22 parts distribution warehouses.
But it doesn’t mean there will be a work stoppage. Contracts expire Sept. 14.
Ford, General Motors and Fiat Chrysler are still making good money, and the UAW will want a bigger piece.
UAW misses getting a foothold in foreign-owned auto assembly plants located in the traditionally anti-union South.