INFO. ON MANUAL TRANSAXLE 1993 INTERIM DESIGN. Saturn Saturn 1993

For 1990-2009 cars

# INFO. ON MANUAL TRANSAXLE 1993 INTERIM DESIGN

#### SUBJECT: Information On Manual Transaxle (MP2/MP3) 1993 Interim Design Changes

#### MODELS AFFECTED: All 1991, 1992 and 1993 vehicles equipped with an MP3 (perf) manual transaxle, and 1993 vehicles equipped with an MP2 (base) manual transaxle built after, and including VIN PZ160920.

PURPOSE: Two major design changes to the MP2 and MP3 manual transaxles have been incorporated as interim 1993 changes.

The lst gear set in the MP2 manual transaxle is now the same as the 1st gear set in the MP3 manual transaxle. With the new gear ratio change, a new calibration will be available on the service stall system (SSS), for vehicles equipped with the MP2 manual transaxle and built after, and including VIN PZ160920.

The elimination of the transaxle case-to-clutch housing gasket and changes to the clutch housing and reverse lever assembly on both the MP2 (base) and MP3 (performance) manual transaxles.

Manual transaxles built after, and including PZ160920 with the above mentioned changes will be referred to as 2nd design, and those built before these changes will be referred to as 1st design. Care must be used to properly identify which design of manual transaxle is in a vehicle when it is brought in for service so that the correct service parts and/or proper powertrain control module (PCM) calibration is used when the vehicle is serviced.

There are two ways of identifying which design manual transaxle is installed in the vehicle.

1. Check the vehicle identification number and compare against the VIN breakpoints given under "MODELS AFFECTED." (Vehicles built before the VIN breakpoint are referred to as 1st design and vehicle built after the VIN breakpoint are referred to as 2nd design.)

2. Change code stamped on clutch housing has been changed from "O" to "1" when this change was implemented.

#### NOTE: Every model year the change code will start back at "O".

GEAR RATIO CHANGE

On the MP2 (base) manual transaxle, the number of teeth on the 1st drive and driven gears can be used to distinguish a 1st design from a 2nd design transaxle. Use the chart below to properly identify the input shaft and the 1st driven gear.

#### NOTE: The gear ratio change does not affect the MP3 (perf) manual transaxle.

#### NOTE: On the input shaft, first gear is the gear closest to the clutch splines and second gear is the gear furthest from the clutch splines. The reverse gear, which is common to all input shafts, is in between the first and second gears and has 13 teeth.

MANUAL TRANSAXLE

Shaft - Input MP2-2nd Design MP2-lst Design MP3-1st & 2nd Design

Part Number 21120184 21001040 21001205

Number of Teeth-lst Gear 12 13 12

Number of Teeth-2nd Gear 21 21 18

Gear - 1st Driven

Part Number 21001302 21001056 21001302

Number of Teeth 39 40 39

Transaxle Assembly 21120380 Base (MP2) 21120100 Base (MP2) 21120101 Perf(MP3) PCM/EC EEPROM ID 21001056 21001302

Federal 7379 3288 3291

California 7388 3322 3325

#### NOTE: If a calibration download is required on a 1993 vehicle, refer to this bulletin to help select the proper calibration from the service stall system (SSS).

#### IMPORTANT: After the new calibration has been installed, vehicle must be driven until operating temperature is reached. This allows the PCM to relearn variations in the fuel system and transaxle electronic controls that improve driveability and engine idle.

CASE - TO - CLUTCH HOUSING GASKET ELIMINATION

When servicing 1991, 1992 and 1993 lst design manual transaxles built with a transaxle case-to-housing gasket, the transaxles must be reassembled with a gasket. Refer to procedures in the "Out-of-Vehicle" section of the appropriate year "Manual Transaxle Service Manual." When servicing 1993 2nd design manual transaxles built without a transaxle case-to-housing gasket, refer to the "1993 New Model Product Guide" or the "1991-1993 Manual Transaxle/Clutch Service Manual," to be published in 1993. For service to the manual transaxle requiring the replacement of the clutch housing, the following procedures must be used.

NEW REVERSE SHIFT LEVER ASSEMBLY SERVICE CLUTCH HOUSING GASKET REQUIRED IF REPLACING HOUSING YEAR/DESIGN ASSEMBLY REQUIRED WITH 2nd DESIGN TRANSAXLE PART NUMBER (Yes/No) (Yes/No)

1991/1st Design 21001017 Yes No

1992-1993/1st Design 21120258 No Yes (P/N 21120283)* 1993/2nd Design 21120258 No N/A

*If a 1992 or 1993 1st design service clutch housing assembly is replaced with a 1992-1993 2nd design service clutch housing assembly, a new reverse shift lever assembly must be installed.

General Motors bulletins are intended for use by professional technicians, not a "do-it-yourselfer". They are written to inform those technicians of conditions that may occur on some vehicles, or to provide information that could assist in the proper service of a vehicle. Properly trained technicians have the equipment, tools, safety instructions and know-how to do a job properly and safely. If a condition is described, do not assume that the bulletin applies to your vehicle, or that your vehicle will have that condition. See a General Motors dealer servicing your brand of General Motors vehicle for information on whether your vehicle may benefit from the information.