UNDERBODY SIDE RAIL CRACKED (INSTALL SIDE RAIL BRACKET). GMC Truck GMC G Van 1993

SUBJECT: UNDERBODY SIDE RAIL CRACKED (INSTALL REINFORCED SIDE RAIL BRACKET)

MODELS: 1992-93 CHEVROLET AND GMC TRUCK G 30 VANS WITH GVWR 8600# (RPO C6P)

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THIS IS AN E X P O R T O N L Y BULLETIN

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CONDITION:

COMMENTS HAVE BEEN RECEIVED ON G 30 VANS WHERE THE UNDERBODY SIDE RAIL HAS CRACKED. THIS CONDITION MAY OCCUR WHEN THE VAN IS CONTINUOUSLY DRIVEN OVER ROUGH TERRAIN OR IF THE VEHICLE IS LOADED OVER THE MAXIMUM GVWR RATING.

CORRECTION:

REMOVE THE EXISTING REINFORCEMENT UNDERBODY BRACKET (FIGURE #1) AND INSTALL THE NEW REINFORCEMENT UNDERBODY SIDE RAIL BRACKET (FIGURE #2).

SERVICE PROCEDURE:

RAISE THE VEHICLE AND PLACE SUITABLE JACK STANDS UNDER THE FRAME SIDE RAILS FOR SUPPORT.

NOTE: A SMALL PIN HOLE MAY BE DRILLED, BUT NOT NECESSARY, AT EACH END OF THE CRACK PRIOR TO WELDING. THE HOLE MUST BE SLIGHTLY LARGER THAN THE CRACK. THIS WILL PREVENT FURTHER MIGRATION OF THE CRACK.

NOTE: THE SHOCK ABSORBER AND THE EXHAUST HEAT SHIELDS SHOULD BE REMOVED FOR THIS REPAIR.

1. THE FRAME RAIL MUST BE CLEANED AND FREE FROM DIRT, PAINT, AND CONTAMINANTS. 2. REMOVE THE EXISTING UNDERBODY SIDE RAIL BRACKET (FIGURE #1) BY GRINDING AWAY THE EDGE WELDS. 3. CLEAN AND SMOOTH OUT THE SIDE RAIL SURFACE. 4. SLIGHTLY V-GRIND A CHANNEL THE FULL LENGTH OF THE CRACK. THE DEPTH SHOULD NOT EXCEED THE FRAME WALL THICKNESS. 5. WELD THE CRACK (OXYACETYLENE WELDING EQUIPMENT IS NOT RECOMMENDED). IT IS RECOMMENDED THAT SMALLER DIAMETER ELECTRODES ON MIG WELDER BE USED MAKING SEVERAL PASSES TO FILL IN THE CHANNEL. 6. INSPECT WELD JOINT TO MAKE SURE THERE ARE NO CRATERS, UNDERCUTS, OR LEFTOVER SCALE. 7. THE WELDED SURFACE SHOULD BE GROUND FLUSH WITH THE SIDE RAIL SURFACE. WHEN FINISHED, RE-COAT THE AREA WITH UNDERCOAT OR AN ANTI-RUST PROTECTOR. 8. INSTALL THE NEW UNDERBODY SIDE RAIL REINFORCEMENT BRACKET. MAKE SURE THAT THE BRACKET IS LINED UP CORRECTLY. THIS CAN BE DONE BY LINING UP THE BOTTOM HOLES AS WELL AS IN-LINE WITH THE SHOCK ABSORBER MOUNTING BRACKET. CLAMP THE BRACKET FIRMLY TO THE SIDE RAIL. WELD THE NEW BRACKET FOLLOWING THE GIVEN POINTS OF REFERENCE LOCATED ON (FIGURE #2). - X = 8 PLACES, 1.0 IN. LONG - * = 3 PLACES, 1.5 IN. LONG 9. AFTER THE BRACKET HAS BEEN WELDED, CLEAN SURFACE ONE MORE TIME. LET AREA COOL AND RE-COAT THE AREA WITH UNDERCOAT OR AN ANTI-RUST PROTECTOR. 10. REMOVE SAFETY STANDS AND LOWER VEHICLE.

SERVICE PARTS INFORMATION:

P/N DESCRIPTION QTY 15693291 LH - UNDERBODY 1 SIDE RAIL BRACKET 15693292 RH - UNDERBODY 1 SIDE RAIL BRACKET

PARTS ARE EXPECTED TO BE AVAILABLE FROM GMSPO ON 10/10/94.

WARRANTY INFORMATION:

FOR VEHICLES REPAIRED UNDER WARRANTY, USE:

LABOR OP DESCRIPTION LABOR TIME E1775 SIDE RAIL REINFORCEMENT (ONE SIDE) 2.0 HRS. E1776 SIDE RAIL REINFORCEMENT (BOTH SIDES) 3.5 HRS.

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

FIGURES: 2

CAPTIONS: FIGURE 1 - OLD UNDERBODY SIDE RAIL BRACKET FIGURE 2 - NEW UNDERBODY SIDE RAIL BRACKET

Object Number: 94696 Size: SF

Object Number: 94355 Size: SF

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.