'99 Outback 315,000 miles with JDM motor done about 130,000 miles, wrecker's yard transmission installed 3 years ago. Third set of suspension struts; noisy vibrating rear diff 45-55 mph about to be swapped for e-bay item. It eats wheel bearings. (JDM motor with slightly higher compression ratio goes like manure off a shiny shovel compared to knackered old USA spec EJ25)

Anyway, this week a strange clattery noise has become apparent from the auto trans bell housing/flywheel area. It sounds like something intermittently loose jumping around between the flywheel and and the tq. convertor drive plate, but I/m pretty sure it is not that. It does not happen when the car is started from cold until iit has

idled for a couple of minutes. Hot restarts it is there straight away. Slowly increase revs and noise gets a bit worse then at 1400 RPM it disappears completely. Returns when RPM decreased. I suspect the Torque Convertor. Car drives fine; no warning lights or leaks.
Anyone come across this or know of it? It would be nice to have some confirmation that the Torque Convertor is the culprit before starting the joyless task of single handed transmission removal - again!

there's a small metal access cover attached by 2 10mm bolts at the bottom of the bellhousing.  if one of those bolts comes loose or it gets bent (easily done when engine/trans have been removed before) it can vibrate/interfere with teeth on torque converter.

 

the flexplate could be cracked.

 

wheel bearings being eaten generally means the hub itself needs replaced.  a bad hub was wearing my bearings out like clock work about every 18,000 miles.  replaced hub and all was well.

Checked cover plate. Plenty of clearance. No witness marks on starter ring from possible contact with cover plate bolts. Still suspect Torque Convertor because rattle does not become audible from cold start until after a couple of minutes at idle; rattle disappears above 1400 rpm; rattle is only there with trans. selector in N or P. Selecting a drive mode causes rattle to disappear.

Check the end play on the crank.  You want to make sure the thrust bearing on the crank isn't lunch.