Nissan Technical Advisor 6/29/2011You know how important changing the engine oil on time is, and the serious damage that can occur in case you don't. Same is the case with changing transmission oil, but this is one area that is very often neglected, resulting in sudden and serious damage to the transmission. One of the prime reasons for automatic transmission problems occurring after the oil is changed is using of the wrong grade of oil. Every manufacturer clearly mentions what grade of oil is to be used in case of an oil change. Make sure that your mechanic used only this grade of oil for the oil change. Using any other grade of oil, however small the difference may be, could prove extremely fatal for your vehicles transmission unit. Check the condition of the transmission oil, replace it with new filter as needed.