The transmission code may be found in two places on the vehicle. One is on the Safety Standard Certification label attached to the left driver's side door lock post. The code appears as a letter in the "Trans'' column of the label.
M or D = 5-speed manual transmission
T = 4-speed automatic transmission (A4LD/4R44E/4R55E)
U = 4-speed automatic transmission (4R70W)
D = 5-speed automatic transmission (5R55E)
The other location is on the transmission body itself. On manual transmissions, the identification number is located on a plate attached to the main transmission case. On the plate you find Ford's assigned part number, the serial number and a bar code used for inventory purposes. On automatic transmissions, the identification number is stamped on plate that hangs from the lower left extension housing bolt. The plate identifies when the transmission was built, it's code letter and model number.
There were two types of manual transmissions used from 1991-99: the Misubishi 5-speed, and the Mazda M5OD. The Mitsubishi 5-speed was only used on 1991-92 4X4 Rangers with the 2.9L engine. All other applications used the M5OD transmission.