New York (CNN Business) The trade war is hurting America's factories, but it's not the only culprit. The strike at General Motors and Boeing's 737 Max crisis are taking a toll as well.

This trifecta of challenges worries analysts and economists that the manufacturing sector could contract for the third-straight month in October. Lower output from American factories could drag down US GDP growth in the third and fourth quarters.

GM GM Boeing's BA American manufacturing is already hurting. Trade tensions between the United States and China have weighed on global demand and input costs. A trade deal could help, but it wouldn't alleviate the impact from the ongoingstrike or the seven-month grounding ofworkhorse jet.

GM and Boeing are two of the largest industrial companies in the United States, and their struggles will make a dent in October factory activity.

"The full effect of the GM strike will be felt in the October data," said Tom Derry, CEO of the Institute of Supply Management. When the strike will be resolved remains unclear.