DETROIT (AP) — Fiat Chrysler will buy back about 300,000 Ram pickup trucks in the biggest such action in U.S. history as part of a deal with U.S. safety regulators to settle legal problems in about two-dozen recalls, two people briefed on the matter say.

Some of the trucks, which are the company’s top-selling vehicle, have steering problems that have lingered without proper repairs for more than two years, according to documents filed with the National Highway Traffic Safety Administration.

The sources say the buyback is part of a larger settlement between the government and the automaker that includes a record $105 million fine and the appointment of an independent recall monitor. Both people asked not to be identified because terms of the deal haven’t been released.

NHTSA has been involved in vehicle buybacks in the past, but never with anywhere near this many vehicles. A buyback usually happens when a problem is so serious that it can’t be fixed and the vehicles need to be taken off the road, and one of this size likely will cost the company hundreds of millions of dollars or more.

It was unclear Sunday exactly what Ram models are covered by the buyback, but documents filed by Fiat Chrysler with the safety agency show a litany of problems in two recalls of the trucks dating as far back as 2011. Some of the problems have yet to be resolved. Trucks in the two recalls include certain 2008 to 2012 Ram 2500 4 by 4 and 3500 4 by 4, the 2012 Ram 3500 4 by 2 Chassis Cab and the 2008 Ram 1500 Mega Cab 4 by 4. Also covered are the Ram 4500 and 5500 from the 2008.

Details of the buybacks are expected to be released shortly by NHTSA.