HARSH GARAGE SHIFT, HARSH OR DELAYED ENGAGEMENT OF PARK TO

SUBJECT: HARSH GARAGE SHIFT, HARSH OR DELAYED ENGAGEMENT OF PARK TO REVERSE OR DRIVE TO REVERSE (INSTALL SRTA AND REFLASH CALIBRATION)

MODELS: 1998 CADILLAC DEVILLE, ELDORADO, SEVILLE 1998 OLDSMOBILE AURORA BUILT PRIOR TO FEBRUARY 16, 1998 WITH HYDRA-MATIC 4T80-E TRANSAXLE (RPO MH1) AND 4.0L OR 4.6L ENGINE (VINS C, Y, 9 - RPOS L47, LD8, L37)

CONDITION: (SEE FIGURE 1) SOME CUSTOMERS OF VEHICLES EQUIPPED WITH THE ABOVE TRANSAXLES BUILT PRIOR TO FEBRUARY 16, 1998 (JULIAN DATE 047) MAY COMMENT ON A HARSH GARAGE SHIFT, SOMETIMES DESCRIBED AS A DELAYED OR HARSH ENGAGEMENT FROM PARK TO REVERSE OR DRIVE TO REVERSE. THE CUSTOMER MAY ALSO DESCRIBE THIS AS A METALLIC "CLUNK" NOISE AT THE END OF THE SHIFT.

CAUSE:

THIS CONDITION MAY BE DUE TO A COMBINATION OF REVERSE CLUTCH CONFIGUARATION, ACCUMULATION AND VEHICLE CALIBRATION OF THIS SHIFT MANEUVER.

CORRECTION:

TRANSAXLE ASSEMBLY PLANTS STARTED PRODUCING TRANSAXLES THAT CONTAIN AN ENHANCED GARAGE SHIFT PACKAGE ON FEBRUARY 16, 1998 (JULIAN DATE 047), TO IMPROVE THE PARK TO REVERSE GARAGE SHIFT FEEL. NEW MODEL CODES WERE INTRODUCED TO HELP TRACK THE IMPLEMENTATION OF THIS CHANGE. IN ORDER TO CORRECT THIS CONDITION ON A CUSTOMER'S VEHICLE WITH A TRANSAXLE BUILT PRIOR TO FEBRUARY 16, 1998 (JULIAN DATE 047),

IT WILL BE NECESSARY TO INSTALL A GOODWRENCH SRTA WITH THE NEW MODEL CODE, AND REFLASH THE CALIBRATION IN THE PCM.

ORIGINAL MODEL CODE UPDATED MODEL CODE BEFORE FEBRUARY 16, 1998 STARTING FEBRUARY 16, 1998 ________________________ __________________________ 8AAN 4.6L (LD8) E/K/K-SPEC 8BBN 4.6L (LD8) E/K/K-SPEC 8ABN 4.6L (LD8) E/K/K-SPEC 8BSN 4.6L (LD8) E/K/K-SPEC 8ADN 4.6L (L37) E/K/K-SPEC 8CLN 4.6L (L37) E/K/K-SPEC 8AJN 4.6L (L37) E/K CAR EXPORT 8CMN 4.6L (L37) E/K CAR EXPORT 8ACN 4.6L (L37) E/K CAR EXPORT 8CRN 4.6L (L37) E/K CAR EXPORT 8MLN 4.6L (L37) E/K/K-SPEC 8CTN 4.6L (L37) E/K/K-SPEC 8MDN 4.0L (L47) G CAR 8DCN 4.0L (L47) G CAR 8MSN 4.0L (L47) G CAR 8DFN 4.0L (L47) G CAR

SERVICE INFORMATION - (SEE FIGURES 2 AND 3)

INDIVIDUAL SERVICE COMPONENT PARTS WILL BE AVAILABLE FOR BOTH THE ORIGINAL 1998 MODEL CODE TRANSAXLES AND THE GARAGE SHIFT UPDATED MODEL CODE TRANSAXLES. PARTS CATALOGING WILL REFERENCE THE FEBRUARY 16, 1998 (JULIAN DATE 047) BREAKPOINT. REFER TO FIGURES 2 AND 3 FOR DEFINITION OF INDIVIDUAL COMPONENT CHANGES. INTERMIXING OF INDIVIDUAL COMPONENTS WILL CAUSE PREMATURE TRANSAXLE FAILURE.

ALSO ATTACHED ARE NEW UPDATED PAGES OF THE 1998 TURM MANUAL SECTION 7 AUTOMATIC TRANSAXLE--4T80-E WITH REVISED ART WORK AND TEXT FOR THE REVERSE CLUTCH ASSEMBLY. THESE PAGES ARE INCLUDED IN THIS BULLETIN AS REFERENCE MATERIAL FOR THE REPAIR OF THE ABOVE CONDITION. PLEASE ALSO REPLACE THESE PAGES IN YOUR 1998 TURM MANUAL.

1998 -- REVISED PAGES ARE: 7-1313, 7-1314, 7-1317 AND 7-1384

PARTS INFORMATION:

PART NUMBER DESCRIPTION 24213654 8BBN 4.6L (LD8) E/K/K-SPEC 24213659 8BSN 4.6L (LD8) E/K/K-SPEC 24213661 8CLN 4.6L (L37) E/K/K-SPEC 24213655 8CMN 4.6L (L37) E/K CAR EXPORT 24213660 8CRN 4.6L (L37) E/K CAR EXPORT 24213656 8CTN 4.6L (L37) E/K/K-SPEC 24213657 8DCN 4.0L (L47) G CAR 24213658 8DFN 4.0L (L47) G CAR

PARTS ARE EXPECTED TO BE AVAILABLE ON JUNE 1, 1998 FROM GMSPO.

CALIBRATION INFORMATION -

NEW PCM

CALIBRATION BROADCAST FILE NUMBER VERSION CODE

9351746 1998 CD ROM DISC 3 CHZH 9351756 1998 CD ROM DISC 3 CHZJ 9351766 1998 CD ROM DISC 3 CHZK 9351776 1998 CD ROM DISC 3 CHZL 9351786 1998 CD ROM DISC 3 CHZM 9351796 1998 CD ROM DISC 3 CHZN 9351806 1998 CD ROM DISC 3 CHZP 9351816 1998 CD ROM DISC 3 CHZR 9351826 1998 CD ROM DISC 3 CHZS 9351836 1998 CD ROM DISC 3 CHZT 9351846 1998 CD ROM DISC 3 CHZU 9351866 1998 CD ROM DISC 3 CHZX 9351876 1998 CD ROM DISC 3 CHZY 9351886 1998 CD ROM DISC 3 CHZZ 9351896 1998 CD ROM DISC 3 CJAB 9351906 1998 CD ROM DISC 3 CJAC 9351916 1998 CD ROM DISC 3 CJAD 9351926 1998 CD ROM DISC 3 CJAF 9351936 1998 CD ROM DISC 3 CJAH 9351946 1998 CD ROM DISC 3 CJAJ 9351956 1998 CD ROM DISC 3 CJAK 9351966 1998 CD ROM DISC 3 CJAL

WARRANTY INFORMATION:

FOR VEHICLES REPAIRED UNDER WARRANTY, USE:

LABOR OPERATION LABOR OPERATION NUMBER DESCRIPTION TIME --------------- ----------- ---------------

K7000 TRANSAXLE ASSEMBLY - USE PUBLISHED LABOR REPLACE OPERATION TIME

ADD: FOR PCM REPROGRAMMING 0.4 HR

FIGURES: 3 ATTACHMENTS: 4

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.

COPYRIGHT 1998. GENERAL MOTORS CORPORATION. ALL RIGHTS RESERVED.