Diagnostic Aids
WARNING: This page is about a different car, the 2003 GMC Sierra, 2003 GMC Cab & Chassis Sierra, 2003 Chevrolet Silverado, and 2003 Chevrolet Cab & Chassis Silverado. However, it is still accessible from the selected car via links, so may be relevant.
An intermittent hard shift may be caused by an intermittent clutch condition. With a self adjusting clutch, the clutch may be between adjustments and not give full clutch release. This might be felt by a low clutch pedal. After several applications, the clutch may adjust properly, to give the proper pedal feel.