A few people here (including me) have mentioned that their factory locker leaks some, but still stays ingaged when needed. Mine leaks alot when cold, but after the diff warms up almost seals completely. Been like that for 4 years now.

1992 montero, cranked t-bars, OME springs, 1-1/2" spring spacers, Homemade rear bumper and roof rack, 33" BFG AT, 1" body lift, Superwinch hubs, '95 SR locking rear axle, was AT - now V5MT1-3 5spd.