I am looking at an exploded view of an Eaton single-reduction differential with the NoSpin option. There is no separate preload adjusting nut. The pinion nut also provides the preload for the two tapered roller bearings that position the pinion in the carrier assembly.
Jerry

"It is better to be silent and be thought a fool than to speak and eliminate all doubt!" - Abraham Lincoln
Cringe and wail in fear, Eloi- - - - -we Morlocks are on the hunt!
There is nothing noble in being superior to your fellow man; true nobility is being superior to your former self. - Ernest Hemingway
Love your enemies and drive 'em nuts!