Not sure what the dealer torqued it to but assume it was properly torqued.
Never noticed any movement but re-torqued it to be sure. With a 3/4" ratchet torque wrench with long handle (about 4' total length), got between 1/4 to 1/2 turn on the nut so feel it's 'gooten tight' now.
The torque wrench never 'let go' at the 450# setting nor when backed off to the 300# setting so believe the torque wrench was way out of calibration or just defective.
Neighbor said to tighten the nut till the lock washer is squashed flat, then give it another 1/2 turn.