Abstract: At approximately 10:50 a.m. on October 30, 2008, Employee #1 and a coworker were repairing a gearbox on the line 14 Case Packer. During this time, the line was locked out to allow the employees to work on the gearbox and sprockets. Before the gearbox was installed, the employees determined that the gear ratio should be 10-1, but received instruction for a 30-1 gear ratio. They emphasized by changing the sprockets to the specified gear ratio, it would increase their rotational speed with a smaller gear. After everything was completed, the coworker was called away from the job to another location. Both employees removed their locks from the line. Employee #1 stayed to run the line and make adjustments to the infeed tension belt. Employee #1 was now working by himself. Employee #1 mentioned that the only way to see what was happening to the cartons was when the line was running. Employee #1 reached around the guard to tap on the infeed belt to check the tension when his right thumb contacted the sprocket and belt. The rotating parts avulsed the tip of the thumb, approximately 25 percent, but did not remove any bones. Employee #1 was transported to a medical center, where he received treatment and was released.