Never done an IFS clamshell, not sure how you could accurately check backlash in one. Also don't remember how the pinion shims work on the yota thirds if they go under the pinion bearing or the race like the dana axles. But I would highly recommend getting some NEW setup bearings or races for the pinion, even with that clam style puller the bearings can only be pressed on and off so many times before they are junked. Also use solid collar spacers instead of the crush sleeves it's more tedious to set the preload but makes it much easier to swap yokes and pinion seals.