The M6 Primary Chain Tensioner makes a smoother ride by reducing annoying vibration, by keeping constant and correct tension at all times. Your transmission will 'click' into gear instead of 'clunk'. It also improves shifting performance while extending the life of your primary chain. You'll swear you just rebuilt your clutch and transmission. Easy installation (generally less than 1 hour for the non-mechanic), it's not necessary to remove your primary chain.