I changed my '98 ITR LSD gearbox fluid with Motul FF-LSD Type 2 75W90 oil (green color fluid). The gearbox takes approx. 2.1-2.2 liters when the gearbox is at room temperature.

This is a very good guide for people like me with minimal hands-on mechanical experience. Loosening both the nuts are tough and definitely needs a breaker bar.

When old fluid is drained, metallic dust and metal particles are visible at the bottom of the oil tray. I think the old Honda MTF has been in there for about 20,000km. Guess it's all wear and tear.

After changing to fresh Motul oil, 2nd to 3rd gear appears to crunch a lot less. Regular and high-rpm quick gear shifts are alot smoother and more direct. Great stuff...