On stripping down the front hubs a bright wear mark could be seen on the dust shield, on the N/S. On checking the hub, it was found to be a 2000>2006 hub. In 2000 Jeep changed the hub off-set by approximately 5mm, requiring the disc to have a shallower off-set. There is no reason why you can not run later hubs on a pre 2000 Jeep but you must change the discs to match.
The garage that carried out this work, could not been aware of the change that Jeep introduced. On the O/S the Wrangler was still running the stock 98 hub. So be aware, make sure the garage you use knows about Jeeps, otherwise they can cause more problems then they fix.