JATCO ELECTROMATIC TRANS. FLUID LEAK

SUBJECT: JATCO ELECTROMATIC TRANSMISSION FLUID LEAK (REPLACE PILOT SLEEVE AND FRONT OIL SEAL)

MODELS: 1988-96 CHEVROLET TILTMASTER AND GMC FORWARD W4 MODELS WITH JATCO ELECTROMATIC TRANSMISSION

CONDITION:

SOME OWNERS MAY COMMENT ABOUT TRANSMISSION FLUID LEAKING ON THE GROUND.

CAUSE:

CONDITION MAY BE DUE TO IMPROPER ALIGNMENT OF THE PILOT SLEEVE IN THE REAR OF THE CRANKSHAFT.

CORRECTION:

REPLACE THE PILOT SLEEVE USING THE SERVICE PROCEDURE AND THE PARTS LISTED BELOW. IF THE FRONT OIL SEAL OR OTHER TRANSMISSION COMPONENTS ARE DAMAGED, THESE PARTS MUST ALSO BE REPLACED. REFER TO SECTION 7A OF THE APPROPROPRIATE SERVICE MANUAL.

SERVICE PROCEDURE -

1. REMOVE THE AUTOMATIC TRANSMISSION AND TORQUE CONVERTER. REFER TO SECTION 7A OF THE APPROPRIATE SERVICE MANUAL. 2. LOOSEN THE SIX FLYWHEEL BOLTS IN SEQUENCE (FIGURE 1,ITEM 1). 3. REMOVE THE FLYWHEEL BOLTS (FIGURE 2, ITEM 4). 4. REMOVE THE FLYWHEEL WASHER (FIGURE 2, ITEM 2). 5. REMOVE THE FLEX PLATE (FIGURE 2, ITEM 5). 6. REMOVE THE FLYWHEEL (FIGURE 2, ITEM 1). 7. REMOVE THE PILOT SLEEVE (FIGURE 2, ITEM 3). 8. INSPECT THE FRONT OIL SEAL FOR DAMAGE. IF THE FRONT OIL SEAL IS DAMAGED, REPLACE THE FRONT OIL SEAL. REFER TO SECTION 7A OF THE APPROPRIATE SERVICE MANUAL.

IMPORTANT: BEFORE INSTALLING THE REPLACEMENT PILOT SLEEVE, MEASURE THE INSERT DEPTH OF THE PILOT SLEEVE.

9. MEASURE THE PILOT SLEEVE INSERT DEPTH. THE DEPTH IS 12 MM (0.47 IN) (FIGURE 3). 10. MEASURE THE PILOT SLEEVE LENGTH. THE LENGTH IS 51.5 MM (2.028 IN) (FIGURE 4). 11. INSTALL THE PILOT SLEEVE USING J 41547 AND J 8092 (FIGURE 5). 12. MEASURE THE PILOT SLEEVE PROJECTION FROM THE CRANKSHAFT. CHECK PROJECTION C=B-A. IF PROJECTION IS C>B-A, REINSTALL THE PILOT SLEEVE. 13. INSTALL THE FLYWHEEL TO THE CRANKSHAFT (FIGURE 2, ITEM 1). 14. INSTALL THE FLEX PLATE TO THE CRANKSHAFT (FIGURE 2, ITEM 5). 15. INSTALL THE FLYWHEEL WASHER (FIGURE 2, ITEM 2). 16. APPLY MOLYBDENUM DISULFIDE GREASE,OR EQUIVALENT,TO THE FLYWHEEL BOLT THREADS AND BOLT HEAD SEAT,EXCEPT FOR NEW BOLTS. 17. INSTALL THE FLYWHEEL BOLTS (FIGURE 2, ITEM 4). 18. TIGHTEN THE FLYWHEEL BOLTS IN TWO STAGES. 1. TIGHTEN THE BOLTS TO 39 N.M (29 LB FT). 2. USE ANGLE TIGHTENING METHOD. MARK THE BOLT HEADS (FIGURE 6,ITEM 1). MAKE A SECOND MARK ON THE WASHER 60-90 DEGREES CLOCKWISE FROM THE FIRST MARK. (FIGURE 6, ITEM 2). TIGHTEN THE BOLTS TO 60-90 DEGREES UNTIL THE MARKS ALIGN. TIGHTEN THE BOLTS IN SEQUENCE (FIGURE 1, ITEM 1). 19. REINSTALL THE TORQUE CONVERTER AND THE AUTOMATIC TRANSMISSION. REFER TO SECTION 7A OF THE APPROPRIATE SERVICE MANUAL.

PARTS INFORMATION:

P/N DESCRIPTION QTY 94455101 SLEEVE, PILOT 1 97133022 CONVERTER, TORQUE 1 97177197 PUMP ASM., OIL 1 97135606 PUMP SEAL, OIL 1

PARTS ARE CURRENTLY AVAILABLE FROM GMSPO.

WARRANTY INFORMATION:

FOR VEHICLES REPAIRED UNDER WARRANTY, USE:

LABOR OP DESCRIPTION LABOR TIME J1400 FLYWHEEL (A/T FLEXPLATE) 3.5 HRS - REPLACE

ADD: PILOT SLEEVE - REPLACE 0.3 HR

ADD: FRONT SEAL - REPLACE 0.2 HR

IMPORTANT: LABOR OPERATION IS CODED TO BASE VEHICLE COVERAGE IN THE WARRANTY SYSTEM.

FIGURES: 06 ATTACHMENTS: 00

FIG.1 - FLYWHEEL BOLTS - REMOVE/INSTALL SEQUENCE 1. FLYWHEEL BOLT 2. FLYWHEEL

FIG.2 - FLYWHEEL AND COMPONENTS 1. FLYWHEEL 2. WASHER 3. PILOT SLEEVE 4. FLYWHEEL BOLT 5. FLEX PLATE

FIG.3 - MEASURING INSERT DEPTH

FIG.4 - MEASURING PILOT SLEEVE LENGTH

FIG.5 - INSTALLING PILOT SLEEVE USING J 41457 AND J 8092

FIG.6 - ANGLE TIGHTENING METHOD 1. REFERENCE MARK ON BOLT 2. REFERENCE MARK ON WASHER

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.

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