I have had to replace a drive flange with a new one,
I can see a slight shoulder on the splines that the spiralok washer needs to position on - but I am struggling to get the dam thing in - any suggestions ?
Not sure if its because there both Britpart or I just need a spot of the old ultra-violence after a rest in the milk bar ?

556445 in the image.

Sorted,
Less violence - more thought.. it kind of screws in with a pair of tiny pliers

I was going to say that. It shouldn't need force to fit. You also only need to gently tighten the nut (12 lb/ ft).