Split Washers should be banned from the planet, they do absolutely nothing and for the most part you are better of with a plain nut torqued to spec.
In really severe conditions there are only three things that works.
#Nord Lock washers
#Mechanical locking measures, like locking tab washers, castle nut & pin, safety locking wire... etc.
And out of all of the above, the castle nut and pin method is probably the most idiot proof.
The suspension of a vehicle is not regarded as "severe conditions" I'm talking rock crusher severe here.
Nylock and distorted thread nuts does come lose about as easy as a plain nut in those conditions. Their benefit is that when they do the nut stays on the fastener preventing things from falling apart all together.
They all have their place, but for the split washer, that place is the nearest landfill.