The $20 million project will create about 200 jobs.
Paccar's Dynacraft division builds some parts for Paccar's Kenworth, Peterbilt and DAF brands.
"We are very pleased to welcome Paccar to McKinney as our newest corporate citizen," Jason Burress, chairman of the McKinney Economic Development Corp., said in a statement. "I believe McKinney will foster an economic environment where Dynacraft's presence in our city will grow well beyond its considerable initial investment."
The McKinney economic development group and the city are still working to finalize the deal, which would receive economic incentives.
Paccar manufactures a variety of trucks and diesel engines, provides financial services and distributes truck parts. McKinney is located about 35 miles north of Dallas.