Its about time to due a service on a 300cd Ive been driving around off and on for the last year.I usually get around to this in Jan so I can keep up with the yearly maintenience.Im curious to know how you guys keep the trannie up to snuff? Just to report on how well these trannies are,Ive never had one go out on me ,this is after owning 6 300cds ,4 190ds ,2 300ds ,2 300tds, and 1 300sd I just bought but still working on it to put it on the road.I use nothing special for fluid ,just cheap STP trannie fluid from the Dollar Store plus the filter.