Product review (5 stars): "Black Tip" Wax Motor died of old age. If you need a spacer, time to replace it.
MLE2000AYW (Neptune Stacker) Washer wouldn't Engage High Speed Spin. Unit had the newer "black tip" Wax Motor (which I thought meant it was still "good") so I added a small spacer to allow it to reach the Spin switch. That only lasted a couple cycles before the old Motor died (Motor died in the"locked" position had to use the Door lock bypass) Ordered this motor and it works perfectly (full reach without a spacer).  On research it would seem my problem wasn't talked about much. Fix videos would show repairs of units with a DIY spacer installed... but attention was focused on non black tipped wax motors and how they WILL fail and burn out control board components. (So replace ASAP if this is you.)

The video I found most useful for my first repair (when I added spacer) suggested the "Black Tip" hasn't "failed in the field". I assume that means not burn out a control board vs just wear out/die of old age.

Wished I'd planned ahead and ordered it early. Hope this is useful to others with a "good" wax motor.  If the retaining clip is holding the Motor firmly in place and the Motor isn't extending all the way to the spin switch after warming up. You should order a new one...