Automatic transaxle, 3 speed (THM 125C)

Years 1982–95, 1998–01 Models 8 Factory citations 18

Also described as Transmission, automatic, 3 speed (THM 125C)Transmission, automatic 3 speed, 3T40Automatic transaxle, 3 speed (THM 125)Transmission, automatic, 3 speed, 3T40Transaxle, 3 speed automatic

Also documented for Buick Chevrolet Oldsmobile

Documented applications

6000 — A-body (1982–1991)

1982–1991 Single-source

matched to the unit by meaning: Wikipedia's 6000 article gives the 6000 the THM 125C (3T40) 1982–1991 but prints no code; the 1984 Celebrity kit heads the code on its own option line, and the air-conditioning entries of 1985–1989 list it only among several units, which dates no year; from 1985 the kit sells the unit as MX1; shared A-body code; cited from the Chevrolet Celebrity kit

GM Heritage factory kit — 1984 Chevrolet Celebrity, p.41.

Fiero (1984–1988)

1984–1988 Single-source

the OSG transaxle page names it the only automatic, every year; the rparts and Halderman lists agree

Grand Am — N-body (1992–1998)

1998 Factory-verified

GM factory document — 1998 pontiac grand am rpo code list, p.1.

Phoenix — X-body (1983–1984)

1984 Single-source

GM engineering code behind the MX1 merchandising option; matched to the Phoenix's unit by meaning: Wikipedia's Phoenix article names the 3 speed Turbo-Hydramatic 125 automatic in its infobox but prints no code; the Citation kit's automatic-transmission weight line for the 2.5 L engine reads "Merchandising Option for MD9, MX1"; 1983 is left out because no listed kit page heads the code that year; shared X-body code; cited from the Chevrolet Citation kit

GM Heritage factory kit — 1984 Chevrolet Citation, p.34.

J2000 / Sunbird — J-body (1982–1987)

1986–1987 Single-source

GM engineering code on the Cavalier power-team pages, the unit the order guides sell as MX1; matched to the Sunbird's unit by meaning: Wikipedia's Sunbird article names the 3 speed Turbo-Hydramatic 125C in its infobox but prints no code; each page prints its model year (1986, 1987) and the 2.0 L power-team line reads "Avail (MD9)"; other years are left out because no listed kit page heads the code on a single-condition line; shared J-body code; cited from the Chevrolet Cavalier kit

GM Heritage factory kit — 1986 Chevrolet Cavalier, p.4.
GM Heritage factory kit — 1987 Chevrolet Cavalier, p.4.

Sunbird — J-body (1988–1994)

1989–1992, 1994 Single-source

matched to the unit by meaning: Wikipedia's Sunbird article gives this generation the 3 speed Turbo-Hydramatic 125C but prints no code; the kit's MVMA specification pages head the automatic line with MD9 (the 1989 automatic page names the unit the THM 125C), and its order guides sell the unit as MX1; 1994 from the MVMA final drive table; 1988 is left out because the 1988 kit names MD9 only inside a multi-unit power-steering weight remark ("1JC00 - 1JE00 & LL8 & MD9"), which dates no year, and 1991 cites p.41 because p.40 prints no legible model year; shared J-body code; cited from the Chevrolet Cavalier kit

GM Heritage factory kit — 1989 Chevrolet Cavalier, p.39.
GM Heritage factory kit — 1989 Chevrolet Cavalier, p.41.
GM Heritage factory kit — 1990 Chevrolet Cavalier, p.15.
GM Heritage factory kit — 1991 Chevrolet Cavalier, p.41.
GM Heritage factory kit — 1992 Chevrolet Cavalier, p.41.
GM Heritage factory kit — 1994 Chevrolet Cavalier, p.39.

Sunfire — J-body (1995–2005)

1998–2001 Factory-verified

Shared J-body code; Chevrolet Cavalier kit.

GM factory document — 1998 pontiac sunfire rpo code list, p.1.
GM factory document — 2001 pontiac sunfire rpo code list, p.1.
GM Heritage factory kit — 1998 Chevrolet Cavalier, p.49.

Trans Sport — U-body / GMT199 (1990–1996)

1992–1995 Single-source

with the LG6; the MVMA power teams pages print it on the transmission line as "MD9 Auto", 3 speed; 1991 is left out because the only 1991 page printing it, the MVMA axle page (p.31, "Automatic Trans (MD9)"), prints its model-year field as 1901, and its MVMA-91 footer form number does not date a page; matched to the unit by meaning: Wikipedia's Trans Sport article names the 3 speed (3T40) automatic from launch and retires it for 1996, and its THM 125 article puts the THM 125 in the U-body vans 1990–1995 with the LG6, but neither prints a code; the 1990 dealer page gives this transmission as MX1 (see MX1); shared U-body code; cited from the Chevrolet Lumina APV kit

GM Heritage factory kit — 1992 Chevrolet LuminaAPV, p.6.
GM Heritage factory kit — 1993 Chevrolet LuminaAPV, p.4.
GM Heritage factory kit — 1994 Chevrolet LuminaAPV, p.4.
GM Heritage factory kit — 1995 Chevrolet LuminaAPV, p.7.

This page aggregates every documented appearance of MD9 in the Pontiac reference. Confidence and citations are shown per application — the same code can be better documented in one year than another.