It is well past the time for my son's Saturn transmission to be serviced. My Nissan guy used a process that exchanges/replaces over 90% of the fluid, but the down side is that pan doesn't come off and the filter doesn't get changed. It is my understanding that conventional transmission fluid "changes" only replaces approximately 60% of the fluid which is great if we all did the 25000 mile thing. This Saturn was bought used and the history is unknown. Which process is best for a Saturn SL1, 1992 vintage and why? This is an opportunity for me to learn.
Thank you in advance.