Product review (5 stars): Easy fix, good part
We all know the symptom, the motor runs and the pump will empty the tub, but the tub will not spin or agitate.  This means the coupler broke.

The original all nylon coupler lasted for 8+ years for me.  I bought the 285753A coupler (has the metal insert) as a replacement and figured this one was way more solid, a much better design and it would last for years.  Not so.

My problem with 285753A is the metal insert would constantly pop out of the nylon.  I tried numerous things to keep this from happening (final try was to use regular and thrust washers so the coupler couldn't move at all) and still had nothing but problems.  I'm not impressed at all with the metal insert design and fitting.

So back to the original all nylon coupler for me.  It fits snugly on the shafts and now look forward to not deal with the insert anymore.  I'll buy a couple extra in case it breaks again, in fact only 1 side broke with the original coupler so kept it for spare parts.  It's such an easy repair that at this point I don't mind replacing the coupler as long as something is really broken with it!

I ordered from Pandora OEM and it is the all nylon design.  With some of the other vendors it's vague as to which one they have.  Pandora spells it out clearly in their ad.