Gears & Axles - gear install problem

So I am installing my gears (10 bolt, Motive 3.42's) and have encountered an unexpected problem. I cannot get the pinion to seat all the way. I am running the bearing down as I am tightening the nut. Tightening the pinion nut down until there is no forward/aft play, then to preload torque. The problem is, I cannot tighten the pinion nut down far enough - there is fwd/aft play in the pinion when the nut stops turning. I cannot run it down any more. I pulled the pinion back out, compared the old stuff with the new, and I cannot see the problem. The new crush sleeve was in place. I would say there is about 1/8 or a tiny bit more movement fwd/aft. I know another way is to have someone hold the pinion in place while I tap the bearing in with a punch, but I was under the impression this could be done either way. There was noone around to help anyway. Maybe it is something incredibly stupid I am not seeing. If so, I'll take the hit on that. Anyone have this problem before?

Just finished mine the other day. What are you tightening the pinion nut with? If it isn't a twin hammer impact (~>400 ft/lbs) or a really long breaker bar with huge forearms, you haven't tightened the pinion nut enough yet. It takes a lot of torque on the pinion nut to seat that front bearing. Once it is seated, all fore/aft movement will cease. Then tighten to proper rotational torque spec (again using very good impact or the he-man breaker bar setup).

Jon

Use a punch and tap the bearing back and forth to seat it onto the pinion gear its really not hard at all. Do you have enough shims behind the front bearing?

I got it. Know what it was? Something many of you probably know, but it was just the crush sleeve that had not crushed yet. I underestimated how much torque was required to crush that thing. Something like 400 ft/lbs. I couldn't get it going with a breaker bar of course. Got a good impact wrench and drove it right in.