REVISED CYLINDER LINER REPLACE PROCEDURES AND PART NUMBERS

THE LINER REPLACEMENT INFORMATION FOUND ON PAGES 6A6-33 AND 6A6-34 OF THE 1986-87 W4 FORWARD SERVICE MANUAL (X-8635) IS INCORRECT. THE CORRECT PROCEDURE IS LISTED BELOW AND SHOULD BE SUBSTITUTED FOR THE ABOVE PAGES. REMOVE OR DISCONNECT (FIGURE 1) TOOL REQUIRED: J-35040, OR EQUIVALENT, LINER REMOVER AND INSTALLER 1. WITH THE PISTON AND CONNECTING ROD REMOVED, TURN THE CRANKSHAFT UNTIL THE CONNECTING ROD JOURNAL FOR THE CYLINDER TO BE SERVICED IS ABOUT HALFWAY DOWN FROM TOP DEAD CENTER (AT 3 OR 9 O'CLOCK). 2. ASSEMBLE THE BRIDGE (G) AND NUT (H) TO THE STUD (I). 3. INSERT THE STUD (I) WITH BRIDGE (G) DOWN THROUGH THE LINER (89). "HOOK" THE BRIDGE INTO THE LINER. PULL UP ON THE STUD TO KEEP THE BRIDGE FULLY SEATED IN THE LINER. 4. INSTALL THE PILOT (F) AND NUT (E) OVER THE STUD (I). 5. SEAT THE PILOT (F) INTO THE LINER. TIGHTEN THE NUT (E) FINGER TIGHT. 6. INSTALL THE BARREL (D) OVER THE STUD (I). 7. INSTALL THE BEARING (B), WASHER (C) AND NUT (A) ON THE STUD (I). 8. TIGHTEN THE NUT (A) TO PULL THE LINER (89) FROM THE BLOCK. LINER SELECTION PROCEDURE 1. THERE ARE FOUR DIFFERENT LINER SIZES, DESIGNATED 1 THROUGH 4. THE ENGINE MAY COME WITH ANY COMBINATION OF LINER SIZES. 2. ALL FOUR SIZE GRADES ARE AVAILABLE FOR SERVICE. THE NEW LINER IS SUPPLIED WITH A PROPERLY MATCHED PISTON, PISTON PIN, AND RINGS. 3. ALWAYS REPLACE A WORN LINER WITH A NEW ONE OF THE SAME SIZE GRADE. 4. THE CYLINDER BLOCK DECK IS MARKED DURING PRODUCTION TO INDICATE BOTH THE CORRECT LINER AND PISTON SIZES (REFER TO FIGURE NO. 2). 5. IF THE BLOCK MARKING IS ILLEGIBLE, MEASURE THE BORE IN THE BLOCK (LINER REMOVED) WITH A DIAL INDICATOR IN SIX LOCATIONS, AS SHOWN IN FIGURE NO. 3. DETERMINE THE AVERAGE OF THE SIX LOCATIONS AND COMPARE WITH THE FOLLOWING CHART. ---------------------------------------------------------------------- BLOCK BORE DIAMETER GRADE LINER GM PART NUMBER AVERAGE MM NUMBER O.D. MM NAT. ASP. TURBO ______________________________________________________________________ 105.001 - 105.010 1 105.011 - 105.020 94050502 94050506 105.011 - 105.020 2 105.021 - 105.030 94050503 94050507 105.021 - 105.030 3 105.031 - 105.040 94050504 94050508 105.031 - 105.040 4 105.041 - 105.050 94050505 94050509 ---------------------------------------------------------------------- INSTALL OR CONNECT (FIGURES 4 AND 5) TOOL REQUIRED: J-35040 LINER REMOVER OR INSTALLER CAUTION: TO HELP AVOID SERIOUS INJURY WHEN HANDLING DRY ICE OR PARTS THAT HAVE BEEN CHILLED: . ALWAYS WEAR HEAVY GLOVES AND SAFETY GOGGLES. . DO NOT SEAL DRY ICE IN AN AIRTIGHT CONTAINER. IT MAY CAUSE THE CONTAINER TO BURST. DRY ICE CAN CAUSE BURNS AND/OR EYE INJURY IF NOT PROPERLY HANDLED. 1. PACK THE SELECTED LINER IN A SUITABLE QUANTITY OF DRY ICE. ALLOW THE LINER TO COOL FOR 35-45 MINUTES. 2. BE SURE THE LINER BORE AND COUNTERBORE AT THE TOP OF THE BLOCK ARE CLEAN. 3. REMOVE THE LINER FROM THE DRY ICE. WEAR HEAVY GLOVES AND SAFETY GLASSES WHEN HANDLING THE CHILLED LINER. DO NOT WRAP A SHOP TOWEL AROUND THE LINER, AS THE CLOTH MAY "STICK" TO THE LINER. THIS MAY CAUSE THE LINER AND CLOTH TO JAM IN THE BLOCK WHEN IT IS INSERTED. 4. QUICKLY INSERT THE LINER INTO THE BLOCK. BE SURE IT STARTS STRAIGHT. 5. ASSEMBLE TOOL J-35040 IN THE LINER (89) AND CYLINDER BLOCK AS SHOWN IN FIGURE 4. 6. TURN NUT (A) UNTIL THE LINER (89) IS FULLY SEATED INTO THE CYLINDER BLOCK. 7. MEASURE THE AMOUNT OF LINER PROJECTION (FIGURE 5). USE A STRAIGHTEDGE AND FEELER GAGE, AS SHOWN. IF PROPERLY INSTALLED, THE LINER SHOULD PROJECT 0.03-0.10 MM (0.0012-0.0039 INCH) ABOVE THE BLOCK GASKET SURFACE. 8. MEASURE LINER BORE OUT OF ROUND AFTER INSTALLATION. PRODUCTION OUT OF ROUND MEASUREMENT IS 0 - 0.05 MM. SERVICE OUT OF ROUND SPECIFICATION MUST NOT EXCEED 0.2 MM.

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.