Originally Posted by dan_vector

Best thing to do is remove the shoe assembly and check for excess wear. The shoes usually last a very long time. Clean everything well and reset the springs as per the manual (download from serpent.com if you don't have the manual). Then try again. Increase the rpm very slowly and feel for the kick. If it doesn't shift then you need to check the springs to make sure they've not gotten weak over time. All else fails replace the shoes and springs which won't be an issue as the SL8 gearbox is still the same on the 977.

Also make sure the drive pin is installed through the shaft. I've left that out before lol!