8 spd XTR M950 hub and 8 spd CS-HG50 8 spd cassette
When I mount the cassette, it's as if there needs to be a spacer on the hub for a tight fit..maybe 2mm. But according to all the info I find, you only need a spacer on a 7 cassette to an 8/9 hub. I see no such spacer for an 8 spd anywhere on the net.
Photo below in which you can see the splines visible between the last two small sprockets.
What am I missing?