TRANSAXLE GEAR WHINE NOISE BETWEEN 20 & 40 MPH. Buick Skylark 1994

SUBJECT: TRANSAXLE GEAR WHINE NOISE BETWEEN 20-40 MPH (REPLACE FINAL DRIVE AND UPDATE PCM CALIBRATION)

MODELS: 1994 BUICK SKYLARK 1994 CHEVROLET BERETTA AND CORSICA 1994 OLDSMOBILE ACHIEVA 1994 PONTIAC GRAND AM

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

TRANSAXLE MODELS: 4CLW, 4PHW, 4WBW, 4WSW

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CONDITION: (FIGURE 1)

SOME OWNERS OF THE LISTED VEHICLES EQUIPPED WITH A HYDRA-MATIC 4T60-E TRANSAXLE MAY EXPERIENCE A FINAL DRIVE GEAR WHINE NOISE. THE FINAL DRIVE NOISE MAY BE DETECTED DURING A LIGHT ACCELERATION OR CLOSED THROTTLE DECELERATION BETWEEN 20 AND 40 MPH.

CAUSE:

THIS CONDITION MAY BE DUE TO A COMBINATION OF THE FINAL DRIVE GEAR TOOTH DESIGN AND VEHICLE POWERTRAIN MOUNTING.

CORRECTION:

NEW FINAL DRIVE ASSEMBLIES WITH A FINE PITCH TOOTH DESIGN ARE NOW AVAILABLE TO REPAIR THIS CONDITION. A 3.05 RATIO FINE PITCH FINAL DRIVE REPLACES THE 3.06 RATIO FINAL DRIVE AND A 3.29 RATIO FINE PITCH FINAL DRIVE REPLACES THE 3.33 RATIO FINAL DRIVE. BECAUSE OF THE DIFFERENT RATIOS OF THE NEW FINAL DRIVE ASSEMBLIES, IT IS ALSO NECESSARY TO INSTALL A REVISED PCM PROM CALIBRATION. ALL 1994 PRODUCTION AND SRTA MODELS CONTINUE TO USE THE CURRENT DESIGN FINAL DRIVE ASSEMBLIES.

SERVICE INFORMATION:

DRIVE THE VEHICLE AND CONFIRM THE FOLLOWING:

O THE NOISE IS ONLY PRESENT DURING A LIGHT ACCELERATION OR CLOSED THROTTLE DECELERATION BETWEEN 20 AND 40 MPH.

O THE NOISE IS NOT PRESENT IN PARK OR NEUTRAL RANGES.

O THE NOISE IS PRESENT IN 2ND, 3RD OR 4TH GEAR (DOES NOT GO AWAY IN 3RD GEAR).

IF ALL OF THE ABOVE CONDITIONS ARE MET, THE FINAL DRIVE ASSEMBLY SHOULD BE REPLACED AND THE PCM CALIBRATION MUST BE UPDATED.

PARTS INFORMATION:

THE FINAL DRIVE ASSEMBLY SHOULD BE REPLACED WITH THE APPROPRIATE PART NUMBERS LISTED AS FOLLOWS: +----------------------------------------------------------+ | PART NUMBER | DESCRIPTION | MODEL | |-------------+-------------------------------+------------| | 24202105 | PACKAGE-FRONT DIFFERENTIAL | 4CLW | | | CARRIER ASSEMBLY (3.05 RATIO) | | |-------------+-------------------------------+------------| | 24202104 | PACKAGE-FRONT DIFFERENTIAL | 4PHW,4WBW, | | | CARRIER ASSEMBLY (3.29 RATIO) | 4WSW | +----------------------------------------------------------+

PARTS ARE EXPECTED TO BE AVAILABLE ON AUGUST 22, 1994.

MEMCAL PART NUMBERS FOR 2.3L (RPO L40 OR LD2) APPLICATIONS ARE AS FOLLOWS: +--------------------------------------------------------------+ | MEMCAL | BROADCAST | SCAN | ENGINE | TRANSAXLE | | PART NUMBER | CODE | ID | APPLICATION | MODEL | |-------------+-----------+------+-----------------+-----------| | 16209248 | BMDM | 9273 | 2.3L L40 (FED.) | 4CLW | |-------------+-----------+------+-----------------+-----------| | 16209245 | BMDL | 9263 | 2.3L L40 (CAL.) | 4CLW | |-------------+-----------+------+-----------------+-----------| | 16209236 | BMDJ | 9243 | 2.3L LD2 (FED.) | 4PHW | |-------------+-----------+------+-----------------+-----------| | 16209240 | BMDK | 9253 | 2.3L LD2 (CAL.) | 4PHW | +--------------------------------------------------------------+

PARTS ARE EXPECTED TO BE AVAILABLE ON SEPTEMBER 26, 1994.

THE NEW "FLASH" PROM FOR 3.1L (RPO L82) APPLICATIONS WILL BE AVAILABLE ON THE SEPTEMBER, 1994 CD RELEASED BY STG. PART NUMBERS ARE AS FOLLOWS:

+--------------------------------------------+ | "FLASH" PROM | ENGINE/VEHICLE | TRANSAXLE | | FILE NUMBER | APPLICATION | MODEL | |--------------+-----------------+-----------| | 16209604 | 3.1L L82 L-CAR | 4WBW,4WSW | |--------------+-----------------+-----------| | 16209624 | 3.1L L82 N-CAR | 4WSW | +--------------------------------------------+

WARRANTY INFORMATION:

FOR VEHICLES REPAIRED UNDER WARRANTY, USE:

LABOR OPERATION: K7750

USE PUBLISHED LABOR OPERATION TIME WITH AN "ADD TIME" OF 0.6 HOUR FOR PCM CALIBRATION UPDATE.

FIGURES: 1 ATTACHMENTS: 0

Object Number: 82873 Size: FS

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.