Your friend is partially right. He is wrong about the transmission shaking and debris, but he is right about doing it yourself. With a shop trans fluid changer machine, they usually filled with Dexron III ATF, which is bad for your car. Doing it yourself guarantees that no wrong fluid will enter the system. He is also right about using specially-formulated ATF for Honda.
One of the things that I like about Honda is transmission service. Just raise your car, put a drain pan under the transmission pan, loosen the drain plug, wait until it stops, install drain plug, remove drain pan, lower the car, and put new fluid.
I don't have the fluid chart with me right now, but just call your friendly Honda service, they will tell you. Or call Checker O'Reilly store close to you. They have it on their computer.
Monday, November 17th, 2008 AT 1:17 AM