WARNING: This page is about a different car, the 2005 Nissan Titan. However, it is still accessible from the selected car via links, so may be relevant.
Measure clearance between shift fork and sleeve. If it is out of specification, replace it with new one.
Standard value
2-4: Less than 0.46 mm (0.018 in)
L-H: Less than 0.46 mm (0.018 in)
Fig 1: Measuring Clearance Between Shift Fork And Sleeve