[ronster]

Correct me if I'm wrong here JFP but the early IMS bearings were also a sealed bearing that had its own lubricant. Once the seal breaks down the lubricant is washed away by the motor oil and the motor oil then becomes the lubricant. As particulates build up in the oil they get into the bearing causing friction and wear that eventually causes the wobble. The problem is that the presence of oil can also indicate an RMS leak and you don't know which it is until the trans is removed and by then you might as well replace both the RMS and IMS.
LN has done away with a sealed bearing and recommends 3K or 5K mile oil changes to keep the oil lubricating the bearing as clean as possible.