General Motors is recalling more than 38,000 Chevrolet Impala police cars in the U.S. and Canada because a part in the front suspension can crack and cause a crash.

The safety recall of cop cars from the 2008 through 2012 model years does not include non-police Chevrolet Impala vehicles, the U.S. National Highway Traffic Safety Administration says on its website.

Media reports say that GM began investigating the problem in February, and in July, its engineers had traced the problem to lower control arms that the company started using in the middle of the 2008 model year.

All the cars were built at GM's factory in Oshawa, Ont.

The NTSA says GM will notify owners, and dealers will replace both front lower control arms, free of charge.

The recall is expected to begin on August 21.