FORD 2004 F-550 v.2 - Manual (Page 297)

Transmission/Transaxle code designations
You can find a transmission/transaxle code on the vehicle certification
label which is located on the door pillar. The following table tells you
which transmission or transaxle each code represents.
Truck application:
Code Transmission Description
Manual transmission
M Manual 5–speed (AKK))
C Manual 5–speed overdrive (Close ratio)
W Manual 5–speed overdrive (Dana ZF)
G Manual 6–speed ZF
Automatic transmission
Y Automatic 4–speed overdrive (CD4E)
U Automatic 4–speed overdrive (4R70W)
T Automatic 4–speed overdrive (4R44E)
E Automatic 4–speed overdrive (4R100)
J Automatic 5–speed overdrive (5R55E)
Electric
H One speed electric
D Automatic 5–speed overdrive (5R44E)
R Automatic 5–speed overdrive (5R55S)
2004 F250/350/450/550 (f23)
Owners Guide (post-2002-fmt)
USA English (fus)
Maintenance and Specifications
297