I think the tranny oil was every 15k while a full service should be done every 50k. I do mine earlier just because being cautious especially for when I drive a little more aggressive than usual at times. Seriously if you could find a good rebuilder you'd probly be best off buying the rebuild kit yourself and dropping the tranny to bring into the shop so you could save a good amount and you know whats going into the tranny vs some other rebuilt tranny.