CHICAGO (CBS) — If you are getting your car fixed anytime soon, you might want to call ahead.

CBS 2’s Charlie De Mar reports that starting on Tuesday, roughly 1,700 mechanics will be on strike at more than 130 new car dealerships.

The reason for the walk-off? Many mechanic’s union contracts are expiring Monday at midnight, and a new deal has yet to be reached.

The union, which represents nearly 2,000 mechanics, couldn’t agree to terms with the new car dealer committee.

“Sunday, a final offer was put forth by the new car dealers committee. It included five percent pay raises almost across the board over the next three years,” said Mark Bilek, who’s with the Chicago Automobile Trade Association.

Bilek says the Mechanics’ Union Local 701 didn’t take the deal, choosing, instead, to strike.

Some of the sticking points for the union are mechanics not getting paid for all the hours they work, non-consecutive days off and increased health care costs.

“We really hoped that we could come to this agreement without a work stoppage,” Bilek said.

Customers like Michael Spada are concerned about what it means for people in need of a repair, saying, “if you need it fixed that day, it’s difficult now. You have to rush around and find another place. What if you are pressed for time?”

For some perspective, there are about 420 new car dealerships in the Chicago-land area.

Anyone who needs to get their car looked at is encouraged to call ahead to make sure the service garage is open and that mechanics are working.