Nissan Navara 1994 Problems

It’s probably not doing any serious damage, but it’s unusual that the synchroes should be worn as is suggested. Make sure you’re fully disengaging the clutch when you shift and try shifting a little slower and giving the synchroes a little more time to work. You could also try double de-clutching to see if that helps. If it proves to be a case of worn synchroes have the gearbox rebuilt and replaced.