CPTN

I know - sorry, but I'm a greenhorn at this.

I've read it's bad to "flush" the transmission fluid on higher-mileage engines, but not to "change" it....what's the difference? Break it down slow for a retarted noobie, please. Also, Honda makes a specific ATF right? I have a 99 civic if it matters.

EJ8_Enthusiast

I think the idea about being bad to flush is flushing pieces of metal through the trans in the process

CPTN

Right...so what's the difference between flushing it and changing it?

Nic

Flushing a tranny on a high mileage vehicle i bad because you are removing all the dirt and grit that has worn on the disc's inside the transmission that now help the discs to grip. Once you remove the grit and crap in there the disc can start to slip and it will increase wear at a rapid rate and can lead to total transmission failure. When you change the fluid you are only removing about 4 quarts ( in hondas ) so you are leaving that grit in there to help the disc stay alive. You are just adding some better fluid in the mix to help increase its life.

On my honda auto I drained the tranny at 160 thousand miles ad I added a quart of Lucas transmission additive.