[lewisnc100]

You don't have auto-locking hubs on your 98, you have full time driveflanges. You can remove the hubs to get to the inner seal, might be where you are getting your squeel. But to get it back on and to set the preload correctly you need a locknut socket to set the high torque in order to seat the bearing, OTC7698 is the part I use. Some use a screwdriver or punch, but the tool makes it easy.

Also if you take off the hub to get to the rear grease seal you've got to remove the outer bearing and with the hub off it's just an easy step to remove the inner seal to get to the inner bearings. Might want to consider a repack while you're in there. Also a perfect time to install Warn Manual Hubs if you've ever considered it.

Another thing you might want to ask the dealer is TSB FA97-001a, it states the following and covers 96-98 pathfinders:

If a 1996-98 Pathfinder vehicle exhibits a high pitch squeal or whistle from the front hub/brake area, the cause may be the front hub dust seal This noise, can be heard while driving next to a wall where the sound is, reflected. The noise is also more likely to be heard after several miles with the front wheels at normal operating temperature. A countermeasure front hub baffle plate is available to resolve these incidents. The countermeasure baffle plates are modified to also function as dust seals. Parts RH 41150-1W400 and LH 41160-1W400.