[KarPop]

I have a question for all you guys that are constantly pumping fresh tranny fluid into your manual box. I need to be schooled on the ways of doing so. Do you flush with fresh fluid then fill with more fresh fluid or do you simply just drain old fluid then fill with fresh fluid?

Total newb to this, seems like there's mix procedures around the internet.

[c4@urdoor]

I say avoid "flushing" with any kind of pressure. It's very unnecessary and potentially harmful to transmissions (mostly autos).
Just drain and fill. Some trans need 2-3 cycles of drain/fill though, as they don't completely drain the first time due to manufacturer design. Again, that's mostly autos.

[HKS PWR]

There's no point in wasting perfectly good (and if you're using synthetic, EXPENSIVE) transmission oil with your way of "flushing" a manual transmission. It's more effective just by draining/filling the transmission fluid, but on a more frequent interval.

[white rocket]

Manual box = drain and fill. As long as you do this semi-frequently you won't have any issues.