THM 3T40 (125C) Update Handbook – ATSG (Automatic Transmission Service Group)
This Update Handbook will explain each change, the parts affected by the change, any parts interchangeability problems created by the change. This Update Handbook will cover all of the changes from start of production up through and including model year 1987, along with common problems, and fixes, for the THM 125 transaxle.
Since the introduction of the THM125 transaxte in model year 1980, there have been many major engineering changes. These changes have affected nearly every part used in the 125 and 125c.
The THM 125 was produced in model years 1980, 81 and early 1982. The THM 125C transaxle, introduced in early 1982, provided the addition of a converter clutch torque converter. The converter clutch was added to increase fuel economy by eliminating the fluid coupling of the transaxle at road load conditions, replacing it with a direct mechanical connection.
Applications:
- 1982–1996 A-body
- 1980–1985 X-body
- 1982–2002 J-body
- 1990-1993 W-body
- 1987–1996 L body
- 1990–1995 U-body vans (with LG6 engine)
- 1984-1988 Pontiac Fiero
CONTENTS
- 1980 Changes
- 1981 Changes
- Driven Sprocket Sleeve
- 3rd Accumulator Check Valve
- 1982 Changes
- Converter Seal Blowout
- 1983 Changes
- 3-2 Coastdown Clunk
- 1984 Changes
- Checking Drive Chain
- 1985 Changes
- 1986 Changes
- 1987 Changes
- 1982 Identification
- 1983 Identification
- 1984 Identification
- 1985 Identification
- 1986 Identification
- 1987 Identification
- Case Identification
Language: English
Format: PDF
Pages: 86
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