Reproduced from a post by RobsFieros
"TRANSMISSION IDENTIFICATION
ASSEMBLY CODE TO TRANSMISSION
1984
NA-MY8
PF-MD9
UM-M19
1985
CD-MD9
PF-MD9
UA-MY7
5ZH-MT2
1986
5UA-M17
6CD-MD9
6PF-MD9
1987
7CPC-MD9
7PSC-MD9
5ZH-MT2
ZNH-MG2
1988
8CPC-MD9
8PSC-MD9
8ZL-MG2"
MY8 is 3.32
MD9 is the auto
M19 is 4.10
As a footnote, in the event the transmission is still in the car or the ID tag is missing, you can identify transmissions by these methods. However, you cannot visually distinguish between the 4:10 and 3:32 ratio 4 speeds.
All 84 manual transmissions were 4 speeds. They all had cable mounts cast onto the case. This is due to the fact that the transmissions were left-over transmissions used in the Front Wheel Drive Citations. Those mounts aren't used in the Fiero. A separate bolt-on mount is used. The case is smooth around the axle seals. It is a two piece case
The 85 and 86 4 speeds do not have cable mounts cast onto the case. There is reinforcement ribbing radiating outward from the axle seals. It is a three piece case.
All 4 speeds have the cables running low to the transmission and they run parallel to one another.
4 speed cables from an 84 are slightly shorter than the cables from the 85 and 86 V6 cars and may create some difficulty if used on a V6 equipped vehicle.
All 85 and later 4 cylinder manuals were 5 speed Isuzu transmissions. They had long cables running parallel to one another and were routed up and over the engine. The transmission has a bolt on cable mount with a yoke that captures the cables to the mount. Transmission shift linkage is stamped metal.
The Getrag transmission has a metal end plate. Transmission cables are routed with one coming up from below and one coming at a downward angle from near the slave cylinder.
Isuzu and Getrag shifters are interchangeable among 5 speed cars.
All pressure plate/clutch disks can be interchanged but the smaller 4 cylinder assemblies installed on a V6 may show premature failure since the friction surface is much smaller.
The Muncie 4-speeds, the Isuzu 5-speeds and the Getrag 5-speeds each use a transmission-specific release bearing which is not interchangeable to other Fiero transmissions.
All manual transmission axles are interchangeable among manual equipped Fieros.
