Review on Dorman 090 204 Drain Plug Piggyback by Jeff Figueroa

This part works with 2005-2010 Mustang 5R55S automatic transmissions and replaces the OEM part 6R3Z-7A010-A. However, Dorman apparently only acquired partial rights to duplicate this part and designed the internal fill hole smaller than the original part, making it incompatible with Ford fluid fill adapter #307-437 (OTC 6604). However, take into account that just one of the OEM parts 6R3Z-7A010-A can cost $30 and Dorman here gives you 5 parts you need as the torx inner cap can get stuck irretrievably (probably you are too search after replacement). All because you need a 5/16 size with 24 profile adapter. So far I've only found one and it's the Mityvac MVA589 ATF refill adapter designed for Volvo, which is actually cheaper than the Ford OEM part. Revain and your local O'Reilly sell them. Compatible with Ford 5R55S and 5R55W Mustangs and Explorers.