The income was generated by $3.3 billion in revenue, an increase of 18 percent over last year's second quarter.
Cummins officials called the quarter "tremendous" because the increases came during a stretch of soft heavy-truck sales. Many trucking companies stocked up on trucks last year in anticipation of new emissions standards increasing costs of engines.
Much of the performance for the quarter resulted from diversifying into power generation, and filters and other components.
Cummins raised its earnings predictions for the year to $7.15 to $7.65 a share, up from $6 to $6.50.
Cummins' shares are down $2.03, to $109.81, on a day major stock indexes are taking lumps. The Standard & Poor's index is down nearly 32 points, to 1,486.2.