The 2000 S that I bought recently was diagnosed, by a reputable indie that does a lot of Porsches, as an IMSB failure... based on metal in the oil filter. I just took the flange off the IMSB this morning and the bearing is fine.
with the seal in place
seal removed... it is a dual row bearing.
When I removed the seal I heard air being sucked into the bearing... so it had maintined a vacuum in the IMS shaft for a couple of months. At least the outer seal was in good shape, I wonder about the inner one.
No oil leaked out and what lubricant is left is rather sad looking, but the bearing itself is not loose and turns just fine.
So how many "IMSB failures" are not... IMSB failures?