I never looked up any spec for lash, but when I replaced the trashed 91/4" spider gears in my D150 the new ones (USA standard gear, Randy's R&P house brand) had almost none. Barely a "tink" out of them when rocking the wheels back and forth. Same story when I replaced the ones in the 8 1/4" in my dad's, too bad that didn't fix the clunk his truck had going into reverse. Niether did the new u-joints, the yoke was fine, and the pinion lash was within spec as I recall. Guess it didn't bug him very much, he'd been driving it for 20 years like that.