SMU - SECTION 6A - REVISED BALANCE SHAFT. Chevrolet Chevy Suburban

SUBJECT: SERVICE MANUAL UPDATE - SECTION 6A - REVISED BALANCE SHAFT SPECIAL TOOLS AND PROCEDURE

MODELS: 1988-90 BUICK ELECTRA 1988-91 BUICK REATTA 1988-95 BUICK LESABRE, PARK AVENUE, REGAL 1988-93 BUICK RIVIERA 1995 BUICK RIVIERA 1992-95 CHEVROLET LUMINA (APV) 1988-92 OLDSMOBILE TORONADO, TROFEO 1988-95 OLDSMOBILE EIGHTY EIGHT, NINETY EIGHT 1992-95 OLDSMOBILE SILHOUETTE 1988-95 PONTIAC BONNEVILLE 1992-95 PONTIAC TRANS SPORT WITH 3800 ENGINE (VINS C, L, K, 1 - RPOS LN3, L27, L36, L67)

THE SPECIAL TOOLS USED TO SERVICE THE BALANCE SHAFT ASSEMBLY HAS BEEN REVISED. KENT-MOORE WILL SEND OUT THE REVISED TOOLS ALONG WITH SPECIFIC INSTRUCTIONS REGARDING THE CURRENTLY RELEASED TOOLS. USE THIS PROCEDURE AND THE NEW TOOLS WHEN SERVICING THE BALANCE SHAFT ASSEMBLY.

TOOLS REQUIRED:

J 6125-B SLIDE HAMMER (ALL) J 21465-13 DRIVE HANDLE EXTENSION J 36996 BALANCE SHAFT INSTALLER J 36995 INCLUDES: J 36995-1 BEARING INSTALLER (ALL) J 36995-5 BEARING AND/OR BUSHING REMOVER (ALL) J 36995-UPD INCLUDES: J 36995-2A BALANCE SHAFT PILOT (ALL) J 36995-3A THREADED ROD (ALL) J 36995-8 BUSHING INSTALLER (VIN K, USE WITH J 36995-1)

REMOVE OR DISCONNECT FIGURES 1 THROUGH 3

1. FLYWHEEL. REFER TO APPLICABLE SERVICE MANUAL. 2. TIMING CHAIN AND CAMSHAFT SPROCKET. REFER TO APPLICABLE SERVICE MANUAL. 3. BALANCE SHAFT RETAINER BOLTS, RETAINER AND GEAR. 4. THREAD J 6125-B INTO FRONT END OF BALANCE SHAFT. 5. BALANCE SHAFT USING SLIDE HAMMER ACTION OF J 6125-B. 6. BALANCE SHAFT REAR PLUG (EXCEPT VIN K). CRANKSHAFT REAR MAIN OIL SEAL HOUSING (VIN K). 7. INSTALL J 36995-5 TO J 36995-3A AND INSTALL ASSEMBLY TO REAR OF ENGINE BLOCK. 8. INSTALL J 36995-2A TO FRONT OF BLOCK AND TO END OF J 36995 ASSEMBLY USING WASHER AND NUT PROVIDED. 9. BALANCE SHAFT REAR BEARING (EXCEPT VIN K), BUSHING (VIN K) BY TURNING THE NUT ON J 36995 ASSEMBLY.

* IT MAY TAKE A CONSIDERABLE AMOUNT OF FORCE TO LOOSEN THE BEARING AND/OR BUSHING FROM THE BORE.

ART NUMBER FS050136 FIGURE 1 -- REMOVING BALANCE SHAFT (ALL)

IMPORTANT

* BALANCE SHAFT, FRONT BEARING, REAR BEARING AND/OR BUSHING ARE SERVICED AS A COMPLETE ASSEMBLY.

INSTALL OR CONNECT

1. MAKE SURE REAR HOUSING GASKET IS REMOVED AND NO DEBRIS REMAINS (VIN K).

2. REMOVE J 36995-5 AND REPLACE WITH J 36995-1 (ALL) AND J 36995-8 (VIN K).

3. INSTALL J 36995 ASSEMBLY TO REAR OF ENGINE BLOCK.

4. INSTALL J 36995-2A TO FRONT OF BLOCK AND TO END OF J 36995 ASSEMBLY USING WASHER AND NUT PROVIDED.

5. DIP BEARING AND/OR BUSHING IN CLEAN ENGINE OIL BEFORE INSTALLATION.

6. BALANCE SHAFT REAR BEARING (EXCEPT VIN K), BUSHING (VIN K) BY TURNING THE NUT ON J 36995 ASSEMBLY. * THE BEARING (EXCEPT VIN K) WILL BE INSTALLED PROPERLY WHEN THE SHOULDER OF J 36995-1 FULLY CONTACTS THE BALANCE SHAFT BORE.

* THE BUSHING (VIN K) WILL BE INSTALLED PROPERLY WHEN J 36995-8 AND J 36995-1 FULLY CONTACTS THE BALANCE SHAFT BORE OR THE CYLINDER BLOCK/TRANSAXLE MOUNTING FLANGE.

ART NUMBER FS053136 FIGURE 2 -- INSTALLING BALANCE SHAFT L36 VIN K

ART NUMBER SPOL3601 FIGURE 3 -- INSTALLING BALANCE SHAFT EXCEPT L36 VIN K

7. REMOVE J 36995 ASSEMBLY.

8. DIP THE FRONT BALANCE SHAFT BEARING INTO CLEAN ENGINE OIL BEFORE INSTALLATION.

9. BALANCE SHAFT INTO BLOCK USING J 36996 AND J 21465-13.

10. TEMPORARILY INSTALL BALANCE SHAFT BEARING RETAINER AND BOLTS.

11. BALANCE SHAFT DRIVE GEAR AND BOLT.

NOTICE: THIS BOLT IS DESIGNED TO PERMANENTLY STRETCH WHEN TIGHTENED. THE CORRECT PART NUMBER FASTENER MUST BE USED TO REPLACE THIS TYPE OF FASTENER. DO NOT USE A BOLT THAT IS STRONGER IN THIS APPLICATION. IF THE CORRECT BOLT IS NOT USED, THE PARTS WILL NOT BE TIGHTENED CORRECTLY. PART OR SYSTEM DAMAGE MAY OCCUR.

TIGHTEN * BOLT TO 22 N.M (16 LB. FT.) PLUS 70 DEGREES.

12. REAR MAIN OIL SEAL HOUSING (VIN K), REAR PLUG (EXCEPT VIN K). MEASURE * BALANCE SHAFT END PLAY. END PLAY SHOULD BE 0.203 MM (0.008 INCH). * BALANCE SHAFT FRONT RADIAL PLAY. RADIAL PLAY SHOULD BE 0.208 MM (0.0011 INCH). * BALANCE SHAFT REAR RADIAL PLAY. RADIAL PLAY SHOULD BE 0.0127- 0.119 MM (0.0005-0.0047 INCH).

13. TURN THE CAMSHAFT SO THAT WITH THE CAMSHAFT SPROCKET TEMPORARILY INSTALLED, THE TIMING MARK IS STRAIGHT DOWN.

14. WITH THE CAMSHAFT SPROCKET AND THE CAMSHAFT GEAR REMOVED, TURN THE BALANCE SHAFT SO THAT THE TIMING MARK ON THE GEAR POINTS ARE STRAIGHT DOWN.

15. CAMSHAFT GEAR. * ALIGN THE MARKS ON THE BALANCE SHAFT GEAR AND THE CAMSHAFT GEAR BY TURNING THE BALANCE SHAFT.

16. TURN THE CRANKSHAFT SO THAT NUMBER ONE PISTON IS AT TOP DEAD CENTER (TDC).

17. TIMING CHAIN AND CAMSHAFT SPROCKET. MEASURE * GEAR LASH AT FOUR PLACES (EVERY 1/4 TURN). * GEAR LASH SHOULD BE 0.050-0.127 MM (0.002-0.005 INCH).

18. BALANCE SHAFT RETAINER AND BOLTS. TIGHTEN * BOLTS TO 30 N.M (22 LB. FT.).

19. TIMING CHAIN AND CAMSHAFT SPROCKET. REFER TO APPLICABLE SERVICE MANUAL.

20. FLYWHEEL. REFER TO APPLICABLE SERVICE MANUAL.

FIGURES: 3 ATTACHMENTS: 0

Object Number: 81913 Size: FS

Object Number: 81912 Size: FS

Object Number: 82806 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 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.