There is currently one technical service bulletin (TSB) for the 5R55S/W, '09-later valve body. This TSB addresses a "whistle noise when hot at an idle in all gears." The fix is to install an updated separator plate, which can be identified by the two small ID holes near the servo bore (see RED ARROWS). The bulletin is #09-21-4, with a date of 11-02-09.
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