For 1990-2009 cars

# INFO. ON FORWARD AND REVERSE SERVO PART CHANGES

#### SUBJECT: INFORMATION ON FORWARD AND REVERSE SERVO PART CHANGES

#### MODELS: 1991 BUICK REATTA 1991-93 BUICK RIVIERA 1991-94 BUICK PARK AVENUE AND REGAL 1992-94 BUICK LESABRE 1994 BUICK CENTURY AND SKYLARK 1991-93 CADILLAC ELDORADO, SEVILLE, SIXTY SPECIAL AND FLEETWOOD (FWD) 1991-94 CADILLAC DEVILLE 1991-94 CHEVROLET LUMINA 1992-94 CHEVROLET LUMINA APV 1994 CHEVROLET BERETTA AND CORSICA 1991-94 OLDSMOBILE NINETY EIGHT AND CUTLASS SUPREME 1991-92 OLDSMOBILE TORONADO AND TROFEO 1992-94 OLDSMOBILE EIGHTY EIGHT AND SILHOUETTE 1994 OLDSMOBILE CUTLASS CIERA AND ACHIEVA 1991-94 PONTIAC GRAND PRIX 1992-94 PONTIAC BONNEVILLE AND TRANS SPORT 1994 PONTIAC GRAND AM

TRANSAXLE APPLICATIONS: HYDRA-MATIC 4T60-E (RPO M13)

TRANSAXLE MODELS: MODELS BUILT BEFORE MARCH 14, 1994 (JULIAN DATE 073)

+--------------------------------------------------------------------+ | INFORMATION | +--------------------------------------------------------------------+

A GARAGE SHIFT PACKAGE, WHICH INVOLVES REVISIONS TO THE FORWARD AND REVERSE SERVO ASSEMBLIES, WAS IMPLEMENTED IN PRODUCTION. THE GARAGE SHIFT PACKAGE PART CHANGES ARE AS FOLLOWS:

**FORWARD SERVO**

- REVISED FORWARD SERVO CUSHION SPRING ONLY.

**REVERSE SERVO**

- REVISED REVERSE SERVO CUSHION AND RETURN SPRINGS.

- ELIMINATION OF THE REVERSE SERVO CURVED SPRING.

- ELIMINATION OF ONE OF THE TWO REVERSE SERVO CUSHION SPRING RETAINERS.

SERVICE INFORMATION: (FIGURES 1 AND 2)

WHEN SERVICING THE FORWARD AND/OR REVERSE SERVO ASSEMBLIES ON 1991- 1994 HYDRA-MATIC 4T60-E TRANSAXLES BUILT BEFORE MARCH 14, 1994 (JULIAN DATE 073) AND SERVO CUSHION AND/OR RETURN SPRING REPLACEMENT IS REQUIRED, FOLLOW THESE GUIDELINES:

**FORWARD SERVO**

- REPLACE THE ORIGINAL FORWARD SERVO CUSHION SPRING WITH THE UPDATED SPRING PART NUMBER LISTED BELOW.

**REVERSE SERVO**

- REPLACE THE ORIGINAL REVERSE SERVO CUSHION AND RETURN SPRINGS WITH THE SPRING KIT PACKAGE PART NUMBER LISTED BELOW.

- REMOVE THE REVERSE SERVO CURVED SPRING AND ONE OF THE TWO REVERSE SERVO CUSHION SPRING RETAINERS.

SERVICE PARTS INFORMATION:

+--------------------------------------------------------------------+ | PREVIOUS | NEW | | | | PART NUMBER | PART NUMBER | DESCRIPTION | MODELS | |-------------+-------------+-------------------------------+--------| | 8668314 | 24201786 | SPRING, FORWARD SERVO CUSHION | ALL | |-------------+-------------+-------------------------------+--------| | 8668121 |USE 24202538 | SPRING, REVERSE SERVO CUSHION | ALL | |-------------+-------------+-------------------------------+--------| | 8649147 |USE 24202538 | SPRING, REVERSE SERVO RETURN | * | |-------------+-------------+-------------------------------+--------| | 8668127 |USE 24202538 | SPRING, REVERSE SERVO RETURN | * | |-------------+-------------+-------------------------------+--------| | - | 24202538 | PACKAGE, SPRING KIT | ALL | | | | (CUSHION AND RETURN, REVERSE) | | +--------------------------------------------------------------------+ * PREVIOUS REVERSE SERVO RETURN SPRING USAGE WAS MODEL DEPENDENT.

PARTS ARE EXPECTED TO BE AVAILABLE ON AUGUST 15, 1994.

#### WARRANTY INFORMATION:

FOR VEHICLES REPAIRED UNDER WARRANTY, USE:

**FORWARD SERVO**

LABOR OPERATION: K6624 USE PUBLISHED LABOR OPERATION TIME.

**REVERSE SERVO**

LABOR OPERATION: K6623 USE PUBLISHED LABOR OPERATION TIME.

FIGURES: 2 ATTACHMENTS: 0

GENERAL MOTORS BULLETINS ARE INTENDED FOR USE BY PROFESSIONAL TECHNICIANS, NOT A "DO-IT-YOURSELFER." THEY ARE WRITTEN TO INFORM THOSE TECHNICIANS OF CONDITIONS OCCURRING 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 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.

COPYRIGHT 1994. GENERAL MOTORS CORPORATION. ALL RIGHTS RESERVED.