Transmission fluid change??

[RJs95s14]

hey i tried to search for this but all i found was how-to's what i am looking for is why..? Why must u change your trans fluid in a manual trans sr20 engine? i have never hurd of such in even vehicles running well over 500 hp. is it something to do with the sr20 engine? i just bought mine and was reading on here and just have never hurd of switing manual trans fluid on a regular basis.. how often do u need to change it and once again why..?

[180fan]

because metal parts need lubrication. your transmission will dump metal bits into the oil and the oil itself breaks down. thus the need to change it.

[RJs95s14]

yea i realize this but i have a 02 cobra mustang pushing 400whp and have never changed the transfluid. never have i been told to by anyone at the dealership. they call for a transflush at 120K but thats it. i see you guys are changing the fluid in your trans every 10K why.. there is no way u are tearing up your gears that bad to have to change it ever 10 changes.. just wondering if it were something to do with the sr20det engine.. or just a personal preferance..

[vancouverbc]

I'm replacing my transmission(1991 240sx) , rear drive axle, and steering gear box fluid, but that is after 280000 kms. i'm doing it mainly to get to know the car better. I doubt if it needs it. If you are racing, i guess ever 10k might be justified.