How much play should there be on the pinion shaft/input yoke on an axle? I'm trying to track down a slight vibration, and noticed I can move my rear axle yoke around (up/down, left/right, etc) about 1/8th of an inch or so - there's almost zero play on my front axle. It does look like it's causing a small leak too. Worn bearing perhaps? Or is that normal? Also, if it is a worn bearing, can I replace that and the seal without removing the carrier - or do they come out through the housing? (on a 12-bolt by the way).