I used Castrol Activ 4T, 15w-40, Bottle States for Continuous protection for motorcycles, Exceeds the requirements of API SG and JASO MA2,

Bottle claims it protects engine clutch and gears.

Personally i diont think its gear related.

I think it has to do with the actual clutch or oil. The only thing that i have a problem with the the lack of adjustment left in the cable. I have taken out all adjustment i can to get 5mm freeplay in the lever, manual states 10-15mm.