Afternoon Ladies and Gents,

I've got a 1997 STi 3 V-Limited wagon with some very poorly looking gearbox fluid.

What can I use to flush the gearbox without doing any damage? I'm concerned that just changing the fluid will leave too much crap behind from the old fluid.

Cheers,
Bryn.

 

I'd suggest just using some cheaper gearbox oil that's okay to mix with your quality gearbox oil and leave it to drain for a while. That way you'll not have much left in there anyway and it's better than having any of the old oil left there.

Don't use engine oils though or any other non-gearbox oil as its different stuff.