Gearbox oil and track use

[stradman]

Hi Guys, just wondering often do you guys change the gearbox oil, in particular with regular track use . Would you do it the same time as the diff?

[XSnake]

Klotz flex drive 30. Every 10 hours of track time. I usually do both at the same time.

[GTSilver]

I usually change both diff and trans oil every other track day as well. Thinking of adding both trans and diff cooler in the future.