WIND NOISE CORRECTION IMPROVED DIAGNOSTIC PROCEDURE

REVISION: 05/13/94

THIS BULLETIN IS BEING REVISED TO ADD THE 1993 MODEL YEAR, REVISE WINDNOISE DIAGNOSTIC FLOWCHART, AND ADD CHART B6 - WINDNOISE REDUCTION PACKAGE, DOOR/WINDOW AREA ALONG WITH WARRANTY INFORMATION FOR THIS SECTION. PREVIOUS DIVISIONAL PUBLICATION NUMBERS WERE:

BUICK 92-10-50 GM OF CANADA 92-2-277 OLDSMOBILE 92-T-136 PONTIAC 92-10-53 ----------------------------------------------------------------------

SUBJECT: WINDNOISE CORRECTION (IMPROVED DIAGNOSTIC PROCEDURE)

MODELS: 1991-93 BUICK PARK AVENUE 1991-93 OLDSMOBILE NINETY EIGHT 1992-93 BUICK LESABRE 1992-93 OLDSMOBILE EIGHTY EIGHT 1992-93 PONTIAC BONNEVILLE

THIS BULLETIN IS INTENDED TO HELP DIAGNOSE AND REPAIR WINDNOISE CONDITIONS IN VARIOUS AREAS OF THE 1991-93 "C" AND 1992-93 "H" VEHICLES. AFTER COMPLETING THE GENERAL DIAGNOSIS SECTION OF THIS BULLETIN, THE CHART PROVIDED WILL DIRECT THE TECHNICIAN TO THE PROBLEM AREA. ALL CHARTS ARE TREATED AS ADD CONDITIONS TO THE ROAD TEST AND DIAGNOSE LABOR OPERATION.

THE BASIC AERODYNAMIC SHAPE OF THE SUBJECT VEHICLES TOGETHER WITH SPECIFIC WINDNOISE RELATED CHANGES (WRAP-AROUND WINDSHIELD, FLUSH SIDE GLASS, QUIET O/S MIRROR, ETC.) HAVE MADE THIS VEHICLE SIGNIFICANTLY QUIETER FOR WINDNOISE THAN ITS PREDECESSORS. WHEN PROBLEMS RELATED TO PARTS FIT OR FUNCTION DO OCCUR HOWEVER, THEIR IMPACT WILL BE MUCH MORE NOTICEABLE AGAINST THE QUIETER BACKGROUND NOISE LEVEL. THIS SERVICE BULLETIN IS INTENDED TO PROPERLY DIAGNOSE THE PROBLEM AND REMEDY THE SITUATION IN THE MOST EFFICIENT MANNER POSSIBLE.

NOTE: THE INFORMATION IS PRESENTED IN A RANKED ORDER BASED ON A COMBINATION OF PARTICULAR LOCATIONS BEING SENSITIVE TO WINDNOISE AND/OR THE LIKELIHOOD OF OCCURRENCE AT THAT LOCATION.

DIAGNOSIS SHOULD NOT BE LIMITED TO INPUT FROM THE CUSTOMER DUE TO THE COMPLEXITY OF PINPOINTING THE NOISE SOURCE. THE PREFERRED TECHNIQUE IS A TWO-STEP APPROACH OF TEST DRIVING THE VEHICLE, FOLLOWED-UP WITH VISUAL INSPECTIONS OF SPECIFIC LOCATIONS. THE DRIVE INSPECTION SHOULD BE USED PRIMARILY TO LOCALIZE WIND RUSHES TO A GENERAL BODY POSITION (I.E., FRONT OR REAR, LEFT SIDE OR RIGHT SIDE) AND TO IDENTIFY SPECIFIC LEAK PATHWAYS. ONCE THIS INFORMATION IS OBTAINED, A VISUAL INSPECTION CAN BE USED TO PINPOINT THE PROBLEM SOURCE.

FOLLOWING IS THE RECOMMENDED METHOD FOR TEST DRIVING AND INSPECTING THE COMPLAINT VEHICLE. NOTE THAT THIS METHOD REQUIRES TWO PEOPLE (TO PROPERLY CHECK ALL LOCATIONS); A STETHOSCOPE (FIGURE 1) WITH 48" OF FLEXIBLE HOSE ATTACHED; AND A ROLL OF 2" WIDE DUCT TAPE. THE CAR SHOULD BE EVALUATED AT SPEEDS OF 50 MPH OR HIGHER (OBSERVE LOCAL SPEED LIMITS), USING SMOOTH, HARD ROAD SURFACES AND WITH OUTSIDE WIND CONDITIONS AS CALM AS IS FEASIBLY POSSIBLE. NOTE THAT UNDER HIGH, GUSTY WIND CONDITIONS, THE OCCUPANT'S PERCEPTION OF WINDNOISE WILL BE ADVERSELY AFFECTED ON ALL VEHICLES.

TEST DRIVE EVALUATION

ATTEMPT TO DEFINE THE GENERAL LOCATION OF THE WINDNOISE SOURCE WITH THE UNAIDED EAR AND DETERMINE IF THE NOISE IS OF A LOUD, GENERALIZED BACKGROUND NATURE (WIND RUSH) AND/OR A SPECIFIC, LOCALIZED NATURE (WIND LEAK). USING A STETHOSCOPE, CHECK: (1) PERIMETER OF WINDSHIELD (FIGURE 2); (2) PERIMETER OF GLASS; (3) PERIMETER OF DROPPING GLASS (ALL DOORS) (FIGURES 2 & 3); (4) PRIMARY DOOR SEALS FROM FRONT BELT UP AROUND TO REAR BELT; AND (5) PERIMETER OF BACKLITE (FIGURE 3). RECORD PROBLEM AREAS AND RELATIVE INTENSITY LEVEL. RETURN TO THE SERVICE AREA AND REFER TO DIAGNOSTIC TREE (ATTACHMENT 1).

NOTE: SOUND LEVELS AT THE ENDS OF DOOR INNER BELT WEATHER SEAL, THE DROPPING GLASS AT THE TOP OF THE CENTER PILLAR AND THE WINDSHIELD ALONG THE FRONT PILLAR ARE GENERALLY HIGHER THAN OTHER LOCATIONS WHEN HEARD THROUGH THE STETHOSCOPE. IT IS A JUDGEMENT CALL AS TO WHETHER THE LEVELS ARE SIGNIFICANTLY HIGHER THAN NORMAL AND REQUIRE CORRECTIONS.

CHART A1 - WINDSHIELD PERIMETER LEAK

A SUSPECTED LEAK IN THE WINDSHIELD URETHANE SEAL SHOULD BE CONFIRMED IN THE SHOP USING ONE OF THE SEVERAL STATIC TEST METHODS. AN ULTRASONIC TESTER SUCH AS KENT-MOORE J26419 OR SNAP-ON AC6600 IS PREFERRED, BUT ANY METHOD, THAT CAN PINPOINT THE EXACT LEAK LOCATION, WILL SAVE VALUABLE TIME.

REPAIR METHOD

THE RECOMMENDED PROCEDURE FOR REPAIRING THE LEAK PATH IS TO REMOVE THE MOLDINGS AS NECESSARY AND FLOOD THE LEAK PATH WITH URETHANE SEALANT. (SEE FIGURE 4 FOR EXAMPLE). COVER THE AREA SURROUNDING THE LEAK SUFFICIENTLY TO AVOID CREATING A NEW LEAK PATH BETWEEN THE LEAK AND THE NEWLY APPLIED SEALANT. GIVE THE NEW SEALANT SUFFICIENT TIME TO CURE AS TO AVOID BLOWING A NEW HOLE THROUGH THE SEALANT.

CHART A2 - WINDSHIELD UPPER REVEAL MOLDING GAPPING

HIGH LEVELS OF WINDSHIELD RUSH CAN BE PINPOINTED TO THE UPPER REVEAL MOLDING THROUGH A SIMPLE INSPECTION. IF ANY LEVEL OF GAPPING IS EVIDENT BETWEEN THE REAR SEALING LIP AND THE ROOF, A WIND RUSH CONDITION WILL EXIST (SEE FIGURE 5). TO CONFIRM THE EXTENT OF THE PROBLEM, COMPLETELY COVER THE ENTIRE MOLDING FROM FRONT PILLAR TO FRONT PILLAR WITH 2" DUCT TAPE AND ROAD TEST. THE RESULT ON A PROBLEM CAR WILL BE A MUCH LOWER BACKGROUND WIND RUSH LEVEL.

REPAIR METHOD:

MINOR GAPS CAN BE CLOSED USING ANY SEALING MATERIAL THAT WILL BOND TO THE SEALING LIP AND THE ROOF'S PAINTED SURFACE, WITHOUT DAMAGING EITHER SURFACE. CLEAR, DOUBLE-SIDED ADHESIVE TAPE SUCH AS SCOTCH ATG ADHESIVE TRANSFER TAPE, NUMBER 969, PART 06493 OR EQUIVALENT WORKS WELL. DO NOT USE QUICK SET SUPER GLUE, AS IT WILL REACT WITH BOTH THE POLYVINYLCHLORIDE (PVC) SEALING LIP AND THE BODY PAINT AND CAUSE MORE SERIOUS REPAIRS.

IF THE GAPPING CONDITION IS EXTREME, REPLACE THE UPPER REVEAL MOLDING. ROAD TEST TO ASSURE THE CONDITION IS REPAIRED.

CHART A3 - WINDSHIELD SIDE REVEAL MOLDING GAPPING TO WINDSHIELD

MODERATE LEVELS OF WINDSHIELD RUSH CAN BE PINPOINTED TO THE SIDE REVEAL MOLDING THROUGH A SIMPLE INSPECTION. IF ANY LEVEL OF GAPPING BETWEEN THE SOFT GLASS SIDE LIP AND THE GLASS IS EVIDENT, A WIND RUSH CONDITION WILL EXIST. (SEE FIGURE 6).

REPAIR METHOD

THE PRODUCTION PART SHOULD BE REMOVED AND CAREFULLY HAND FORMED TO CLOSE THE GAP BETWEEN THE MOLDING AND THE WINDSHIELD. REINSTALL THE PART AND INSPECT FOR A GAPPING CONDITION. REPEAT PROCESS UNTIL ALL GAPPING IS REMOVED. USE CARE NOT TO OVER BEND THE PART IN ANY ONE LOCATION AND CAUSE AN APPEARANCE PROBLEM. ROAD TEST TO ASSURE THE CONDITION IS REPAIRED.

CHART A4 - GLASS RUN CHANNEL GAPPING TO WINDSHIELD SIDE REVEAL MOLDING

MODERATE LEVELS OF WIND RUSH CAN BE DETECTED WHEN THE AUXILIARY SEALING LIP OF THE GLASS RUN CHANNEL IS GAPPING ALONG THE FRONT WINDSHIELD PILLAR. THE CONDITION IS MOST SENSITIVE TO GAPS AT THE VERY TOP OF THE PILLAR. IN THE JOINT BETWEEN THE WINDSHIELD SIDE REVEAL MOLDING, WINDSHIELD UPPER REVEAL MOLDING AND ROOF DRIP RAIL (SEE FIGURE 7).

REPAIR METHOD:

THE SIMPLEST METHOD OF REPAIR IS TO CAREFULLY PULL THE ADHESIVE SEALING TAPE THAT HOLDS THE GLASS RUN CHANNEL TO THE DOOR FRAME LOOSE FROM THE DOOR. REPOSITION THE GLASS RUN CHANNEL IN A WAY THAT PULLS THE AUXILIARY LIP FURTHER INTO THE DOOR OPENING. IT WILL BE NECESSARY TO APPLY A LENGTH OF DOUBLE FACE TAPE SUCH AS 3M PART NO. 06382 SCOTCH-MOUNT, OR EQUIVALENT, TO PROPERLY RE-ATTACH THE RUN CHANNEL TO THE DOOR FRAME. IN SOME CASES WHERE THE CONDITION CANNOT BE CORRECTED BY THE SIMPLE ADJUSTMENT, THE DOOR FIT ITSELF WILL HAVE TO BE ADJUSTED TO CORRECT THE CONDITION. ROAD TEST TO ASSURE THE CONDITION IS REPAIRED.

CHART A5 - GENERAL RUSH IN FRONT PILLAR FROM BASE TO ROOF

A HIGH LEVEL OF WIND RUSH IN THE FRONT PILLAR, THAT CANNOT BE ASSOCIATED WITH CHARTS A1, A3 OR A4, MAY BE INTERNAL TO THE PILLAR ITSELF. THE PILLAR HAS AN EXPANDABLE FOAM PLUG IN ITS BASE AND MAY NOT BE COMPLETELY SEALED. NOISE FROM THIS SOURCE WILL BE FAIRLY UNIFORM WHEN CHECKED ALL ALONG THE INSIDE OF THE WINDSHIELD DURING THE ROAD TEST. BEFORE REPAIR IS STARTED, COVER THE WINDSHIELD SIDE REVEAL MOLDING AND ITS MATING SURFACE ON THE WINDSHIELD AND THE DOOR GLASS RUN CHANNEL WITH DUCT TAPE (SEE FIGURE 8) AND ROAD TEST AGAIN. IF THERE IS NO IMPROVEMENT, PROCEED WITH THE REPAIR METHOD AS DESCRIBED BELOW. IF THE TAPING IMPROVES THE CONDITION, RE-EVALUATE FOR CONDITIONS A1 AND/OR A3 AND/OR A4.

REPAIR METHOD:

REMOVE THE FRONT PILLAR GARNISH MOLDING TO EXPOSE THE PILLAR. USING A DOUBLE-EXPANDED POLYURETHANE FOAM (AVAILABLE FROM A BUILDING SUPPLY OUTLET), FILL THE LOWER ONE QUARTER OF THE PILLAR THROUGH THE BOTTOM SLOTTED HOLE (SEE FIGURE 9). USE CAUTION NOT TO ALLOW THE FOAM TO COME IN CONTACT WITH OTHER PARTS AND NOT TO OVERFILL THE PILLAR. THE FOAM WILL MORE THAN DOUBLE ITS VOLUME DURING THE CURING PROCESS.

NOTE: FIRST, SQUIRT A SMALL AMOUNT OF FOAM INTO A WASTEBASKET TO GET AN IDEA OF HOW FAST IT COMES OUT OF THE CAN AND TO MAKE SURE THE FOAM EXPANDS PROPERLY.

PLACE A PIECE OF TAPE OVER THE SLOT UNTIL THE FOAM CURES. AFTER THE FOAM HAS CURED, REMOVE THE TAPE AND REINSTALL THE GARNISH MOLDING. ROAD TEST TO ASSURE THE CONDITION IS REPAIRED.

CHART B1 - INNER DOOR BELTLINE LEAKS AT SEVERAL LOCATIONS

STRONG WIND LEAKS OF RELATIVELY THE SAME INTENSITY HEARD AT LOCATIONS 1, 2, 3, AND 4 (SEE FIGURE 10), ARE USUALLY ASSOCIATED WITH AN IMPROPERLY FITTING DOOR OUTER WEATHER SEAL. A QUICK VISUAL INSPECTION WILL CONFIRM THE PROBLEM. ANY GAPPING THAT OCCURS BETWEEN THE WEATHER SEAL SEALING LIP AND THE DOOR SURFACE CAN CAUSE EXCESSIVE WIND NOISE.

REPAIR METHOD:

REMOVE COMPLETE WEATHER SEAL ASSEMBLY, USING CARE NOT TO DAMAGE PAINT SURFACE. INSPECT CLIP TANGS AND REPOSITION ANY TANGS BENT DURING INITIAL INSTALLATION AND/OR REMOVAL. REINSTALL WEATHER SEAL BY ALIGNING THE REAR EDGE OF SEALING STRIP TO THE REAR EDGE OF DOOR AND ENGAGING (7) CLIPS INTO SLOTS ON DOOR PANEL. THIS IS DONE EASIEST BY INSERTING THE FRONT CLIP FIRST AND WORKING REARWARD. AGAIN, USE CAUTION NOT TO DAMAGE PAINTED SURFACE. THE WEATHER SEAL IS FULLY SEATED WHEN OUTER SEALING LIP IS FULLY COMPRESSED ON DOOR SURFACE AS SHOWN IN FIGURE 11. ROAD TEST TO ASSURE THE CONDITION IS REPAIRED.

CHART B2 - INNER DOOR BELTLINE LEAKS AT SPECIFIC LOCATIONS ONLY

STRONG WIND LEAKS HEARD AT A SPECIFIC LOCATION ONLY ON THE INNER BELT CAN GENERALLY BE ASSOCIATED WITH MISSING OR MISPLACED FOAM PATCHES AT LOCATIONS 1 OR 4 (SEE FIGURE 12) OR A PROBLEM WITH THE OUTSIDE MIRROR IF THE NOISE IS INTENSE AT LOCATIONS 2 AND 3. PROBLEMS WITH THE MIRROR CAN BE CONFIRMED BY INSPECTING THE MIRROR FOR CORRECT POSITIONING OF THE MIRROR GROMMET AND THE CORRECT INSTALLATION OF THE MIRROR MOUNTING GASKET.

REPAIR METHOD:

LOCATIONS 1 OR 4: THE CORRECTION TO NOISE AT THESE LOCATIONS IS TO CAREFULLY STUFF SMALL PATCHES OF SOFT FOAM IN THE OPENINGS BETWEEN THE INNER BELT WEATHER SEAL LIP, THE DOOR GARNISH MOLDINGS AND THE INTERIOR TRIM PAD. DO NOT PUT FOAM BETWEEN THE LIP AND THE DROPPING GLASS ON THE REAR OF THE FRONT DOORS OR THE FRONT OF THE REAR DOORS, AS IT WILL SIMPLY TEAR AWAY WHEN THE GLASS IS DROPPED.

LOCATIONS 2 AND 3: IF INSPECTION IDENTIFIES THAT THE GROMMET OR THE BASE GASKET IS INCORRECTLY INSTALLED, CORRECT THE PROBLEM AND ROAD TEST FOR IMPROVEMENT. IF THE MIRROR DOES NOT TURN UP A PROBLEM SOURCE, RE-EVALUATE THE OUTER BELT WEATHER SEAL FOR GAP TO THE DOOR SURFACE. CORRECT AS OUTLINED IN CHART B1.

CHART B3 - DROPPING GLASS PERIMETER LEAKS

DROPPING GLASS PERIMETER LEAKS NOT CORRECTED THROUGH CHARTS B1 OR B2 WILL GENERALLY BE ASSOCIATED WITH A WEAK ENGAGEMENT OF THE GLASS INTO THE GLASS RUN CHANNEL SEALING SECTIONS. A VISUAL INSPECTION OF THE PROBLEM AREA SHOULD CHECK FOR SUCH THINGS AS LOCAL DISCREPANCIES IN THE GLASS EDGE OR GLASS RUN CHANNEL SEALING LIPS; EXPOSED EDGES OF GLASS THAT DO NOT PENETRATE INTO GLASS RUN CHANNEL; UNEVEN 'WINK-OVER' OF THE OUTER SEALING LIP ALONG THE TOP EDGE AND DOWN THE VENT GLASS DIVISION POST; AND A GAP BETWEEN THE OUTER SEALING LIP AND GLASS ON THE VERTICAL LEG (REAR OF FRONT DOOR ONLY), (SEE FIGURE 13).

REPAIR METHOD:

FIRST, IDENTIFY IF THE PROBLEM IS A VERY LOCAL LEAK CAUSED BY A PART DISCREPANCY IN EITHER THE GLASS OR THE GLASS RUN CHANNEL. OFTEN HARD SPOTS ON THE GLASS RUN CHANNEL CAN BE WORKED OUT WITHOUT REMOVING OR REPLACING PARTS. GLASS IRREGULARITIES CAN LIKEWISE BE MINIMIZED BY ADJUSTING THE GLASS TO IMPROVE THE FIT IN THE PROBLEM AREA. IF SIMPLE FINESSE TECHNIQUES DO NOT WORK, THEN REPLACE PARTS AS REQUIRED. IF THE PROBLEM IS IDENTIFIED AS LACK OF PENETRATION/WINK-OVER AT THE TOP OF THE DOOR AND/OR ALONG THE VENT GLASS DIVISION POST (FRONT DOOR ONLY) OR APPLIQUE (REAR DOOR ONLY); THEN READJUST THE GLASS TO OPTIMIZE PENETRATION/WINK-OVER. GENERALLY THIS MEANS MOVING THE GLASS UP AND REARWARD IN THE SASH ON THE FRONT DOOR AND UP AND FORWARD IN THE SASH ON THE REAR DOOR. CYCLE THE GLASS SEVERAL TIMES (WITH THE ENGINE RUNNING) TO EVALUATE IMPROVEMENT OF THE GLASS POSITION AND ROAD TEST AGAIN.

IF THE PROBLEM IS ALONG THE REAR VERTICAL LEG OF THE FRONT DOOR AND GAPPING BETWEEN GLASS AND THE OUTER SEALING LIP IS EVIDENT, REFER TO CORPORATE BULLETIN #201003 FOR REPAIR (PREVIOUS DIVISIONAL PUBLICATION NUMBERS WERE: BUICK - 92-10-41; GM OF CANADA - 92-2-197; OLDSMOBILE - 92-T-65; AND PONTIAC - 92-10-48).

CHART B4 - FIXED GLASS PERIMETER LEAKS (VENT GLASS)

A URETHANE SEAL EXTENDS FROM THE TOP OF THE DIVISION POST DOWN TO THE BELT, EXCLUDING THE DIVISION POST ITSELF (SEE FIGURE 14). LEAKS MAY SOMETIMES OCCUR IN THE URETHANE SEAL, PARTICULARLY AT THE TOP OF THE DIVISION POST. THE RESULT IS A HIGH FREQUENCY WIND LEAK THAT IS EASILY HEARD WITH THE STETHOSCOPE.

REPAIR METHOD:

PACK SMALL AMOUNTS OF A THUMBGRADE TYPE SEALING MATERIAL OR A SUITABLE EQUIVALENT BETWEEN THE GLASS SURFACE AND THE DOOR GARNISH MOLDING SUFFICIENTLY TO CLOSE OUT THE LEAK PATHWAY IN THE URETHANE SEAL. ROAD TEST AND REPEAT IF NECESSARY.

CHART B5 - DOOR PRIMARY SEAL LEAKS

DOOR-TO-BODY PRIMARY SEAL LEAKS MAY OCCUR GENERALLY FOR ONE OF TWO REASONS. EITHER THE SEAL IS NOT SEATED CORRECTLY TO THE BODY FLANGE AND DOES NOT FOLLOW THE DOOR SEALING SURFACE OR THE DOOR ITSELF IS OUT AWAY FROM THE BODY SUCH THAT THERE IS NOT SUFFICIENT CONTACT WITH THE SEAL.

REPAIR METHOD:

WITH THE DOOR CLOSED, INSPECT FOR SEAL CONTACT WITH THE DOOR. IF THE PROBLEM IS ONE OF IMPROPER SEAL CONTACT DUE TO MISALIGNMENT WITH THE DOOR SURFACE, PULL THE ENTIRE SEAL OFF THE BODY FLANGE AND REINSTALL AS FOLLOWS (SEE FIGURE 15): POSITION THE JOINT IN THE CENTER OF THE ROCKER AND INSTALL ON FLANGE WORKING FORWARD TOWARD HINGE PILLAR: CONTINUE AROUND DOOR OPENING USING CARE TO SEAT THE WEATHERSEAL SECURELY ONTO THE FLANGE, PARTICULARLY IN THE CORNERS. WHEN THE SEAL IS COMPLETELY INSTALLED, GO BACK OVER THE ENTIRE LENGTH AND MAKE SURE NO MATERIAL HAS PULLED OFF THE FLANGE. IF THE LEAK SOURCE IS DETERMINED TO BE A RESULT OF TOO MUCH GAP BETWEEN THE DOOR AND BODY; DOOR ADJUSTMENTS WILL BE REQUIRED TO CLOSE UP THE GAP. REINSPECT AND ROAD TEST AFTER CORRECTIONS ARE MADE.

CHART B6 - WINDNOISE REDUCTION PACKAGE; DOOR/WINDOW AREA

DESCRIPTION:

THE C/H WINDNOISE REDUCTION PACKAGE KIT, P/N 12537264, CONSISTS OF A NUMBER OF NEW OR REVISED FOAM PATCHES ALONG WITH SEVERAL ADJUSTMENT PROCEDURES WHICH ADDRESS THE MOST COMMON SOURCES OF WINDNOISE FROM THE DOORS OF THE "C" AND "H" CARS. THIS IS DONE BY SEALING LEAK PATHS, IMPROVING DROPPING GLASS SEALING, AND BLOCKING NOISE TRANSMISSION PATHS. THESE MEASURES WILL ALSO REDUCE SOME TRANSMISSION OF TRAFFIC AND ROAD NOISE THROUGH THE DOORS.

THE PACKAGE HAS BEEN INSTALLED IN PRODUCTION VEHICLES SINCE MAY, 1993. INSTALLATION OF THE PACKAGE ON OLDER VEHICLES WILL SIGNIFICANTLY REDUCE THE OVERALL LEVEL OF WINDNOISE. THE BENEFIT IS MOST PRONOUNCED IN CROSSWINDS, REDUCING THE FAMILIAR NOISE OF WIND GUSTS.

INSTALLATION OF THE PACKAGE WILL REQUIRE REMOVAL OF THE GLASS RUN CHANNELS. ON 1991 AND EARLY 1992 MODELS, THE RETENTION CLIPS ARE FREQUENTLY BROKEN DURING REMOVAL. LATER MODELS FEATURE A REVISED CLIP WHICH IS LESS SUSCEPTIBLE TO BREAKAGE. HOWEVER, THERE IS STILL A RISK OF CLIP SEPARATION, GLASS BREAKAGE, OR OTHER DAMAGE TO THE GLASS RUN CHANNEL. THEREFORE, IT IS RECOMMENDED THAT REPLACEMENT PARTS BE READILY AVAILABLE PRIOR TO INSTALLATION OF THE PACKAGE.

DIAGNOSIS:

VISUALLY INSPECT THE VEHICLE FOR PROPER ASSEMBLY AND FIT. IN PARTICULAR, CHECK FOR IMPROPERLY SEATED BELT STRIPS, INSUFFICIENT PENETRATION OF GLASS INTO SEALS (THE REAR DOOR UPPER B-PILLAR IS FREQUENTLY A PROBLEM), AND GAPS OR LOOSE SEALS BETWEEN THE FRONT DOOR B-PILLAR APPLIQUE AND THE SIDE GLASS.

TEST DRIVE THE VEHICLE AT HIGHWAY SPEEDS, USING A STETHOSCOPE TO IDENTIFY SPECIFIC SOURCES OF WINDNOISE. THE DESCRIPTIONS OF THE COMPONENTS OF THE PACKAGE WILL IDENTIFY THE AREAS WHICH THEY AFFECT. AFTER THE WORK IS COMPLETED, PERFORM A SECOND TEST DRIVE TO VERIFY THE RESULTS.

COMPONENT DESCRIPTIONS:

FRONT AND REAR DOOR INSULATORS (FIGURES 16 AND 17): THESE ARE 25MM THICK URETHANE FOAM FLOCKS TREATED TO REPEL WATER AND TAKE ON THE CHARACTERISTICS OF CLOSED-CELL FOAM WHEN COMPRESSED. THE INSULATORS HAVE THREE PURPOSES - TO SEAL THE BASE OF THE FIXED GLASS, TO FILL THE SHEET METAL NOTCH AT THE END OF THE DOOR, AND TO PREVENT TRANSMISSION OF NOISE UP THE GARNISH MOLDING. THIS REDUCES NOISE WHICH IS HEARD ALONG THE LEADING EDGE AND BASE OF THE FRONT FIXED GLASS, AND AT THE LOWER REAR CORNER OF THE REAR FIXED GLASS. THE INSULATORS ARE INSTALLED AT THE EXTREME FRONT OF THE FRONT DOOR AND THE REAR OF THE REAR DOOR, RESTING ON THE STRAP BETWEEN THE INNER AND OUTER DOOR PANES AT THE BASE OF THE FIXED GLASS. (THE OLDSMOBILE "H" REAR DOOR INSULATOR IS THE EXCEPTION. IT RESTS DIRECTLY ON THE DOOR INNER PANEL). THE FRONT DOOR INSULATOR (FIGURE 17) HAS A NOTCH WHICH FITS OVER THE FRONT EDGE OF THE DOOR. THERE MAY BE A SMALL FOAM PATCH IN THIS AREA WHICH MUST FIRST BE REMOVED. THE UPPER PORTION OF THE INSULATOR WRAPS AROUND THE BASE OF THE A-PILLAR INSIDE THE GARNISH MOLDING. IT IS NECESSARY TO REMOVE THE EXISTING FOAM PATCH FROM INSIDE THE GARNISH. SIMILARLY, THE BUICK/OLDSMOBILE REAR DOOR INSULATOR (FIGURE 16) HAS A NOSE WHICH FITS INTO THE NOTCH IN THE DOOR END PANEL, WHILE THE UPPER PORTION WRAPS AROUND THE BASE OF THE C-PILLAR INSIDE THE GARNISH MOLDING. BECAUSE OF ITS UNIQUE PILLAR ANGLE, THE PONTIAC REAR DOOR INSULATOR (FIGURE 16) SIMPLY RESTS IN THE CORNER OF THE DOOR AND WRAPS AROUND THE PILLAR IN A SIMILAR MANNER.

TRIANGLE FOAM PATCH (FIGURE 18): THIS PVC FOAM PATCH ATTACHES TO THE INSIDE OF THE MOLDED TRIANGLE AT THE BASE OF THE DIVISION POST ON THE GLASS RUN CHANNEL. IT SEALS TO THE INNER BELT STRIP AND REDUCES NOISE TRANSMISSION FROM THE DOOR CAVITY. ON BUICKS AND PONTIACS, THE SAME V-SHAPED PART IS USED ON BOTH SIDES OF THE VEHICLE. OLDSMOBILE PATCHES ARE TALLER AND ARE SPECIFIC TO EACH SIDE OF THE VEHICLE.

B-PILLAR PATCH AND "L" FOAM (FIGURES 19 AND 20): THE PVC FOAM B-PILLAR PATCH REPLACES THE SQUARE OR L-SHAPED PATCH AT THE UPPER B-PILLAR CORNER OF EACH DOOR. IT PROVIDES A CONTINUOUS SEAT TO THE GLASS RUN CHANNEL ACROSS THE SAME SPACE BETWEEN THE UPPER RETAINER AND THE APPLIQUE, WHILE COVERING THE SHEET METAL NOTCH IN THE CORNER. THE PATCH WORKS TOGETHER WITH THE "L" FOAM WHICH IS APPLIED TO THE GLASS RUN CHANNEL BETWEEN THE RETAINING LIPS AS SHOWN IN FIGURE 20. TOGETHER, THESE TWO PATCHES SEAL THE UPPER CORNER OF THE GLASS RUN CHANNEL TO THE DOOR FRAME TO ELIMINATE AIR LEAKS AND THE ASSOCIATED NOISE. (FRONT DOOR B-PILLAR PATCH SHOWN IN FIGURE 19, BACK DOOR IS SIMILAR).

APPLIQUE FOAM STRIPS: PVC FOAM STRIPS ARE APPLIED TO THE BACK OF THE B-PILLAR APPLIQUES, ON THE ANGLED SURFACE ADJACENT TO THE MOUNTING SURFACE. THERE MAY BE TWO RECTANGULAR FOAM PATCHES OR HARD RUBBER SPACERS ON THAT SURFACE WHICH MUST BE REMOVED. THIS PREVENTS LEAKAGE BEHIND THE APPLIQUE WHICH CAUSES NOISE ALONG THE B-PILLAR EDGE OF THE DROPPING GLASS.

PROCEDURES:

REMOVE THE EXTERIOR BELT STRIP, INTERIOR DIVISION POST GARNISH, AND GLASS RUN CHANNEL. IF THE GLASS RUN IS TO BE RE-USED, INSPECT THE RETAINING CLIPS FOR BREAKAGE AND REPLACE DOUBLE-SIDED TAPE AS REQUIRED. REMOVE THE B-PILLAR APPLIQUE AND TWO GARNISH MOLDINGS. REMOVE THE FOAM PATCH FROM INSIDE THE BASE OF THE FRONT DOOR A-PILLAR GARNISH. REMOVE THE SQUARE OR L-SHAPED PATCH FROM THE TOP CORNER OF THE B-PILLAR. REMOVE THE RECTANGULAR PATCHES OR RUBBER BUMPERS FROM THE BACK OF THE B-PILLAR APPLIQUE. THE PATCHES MAY ADHERE TO THE DOOR FRAME WHEN THE APPLIQUE IS REMOVED. INSTALL NEW B-PILLAR PATCH PER FIGURE 19.

INSTALL THE FRONT DOOR INSULATOR BY INSERTING IT BETWEEN THE INNER AND OUTER DOOR PANELS, RESTING ON THE SHEET METAL STRAP. HOOK THE FRONT OF THE INSULATOR OVER THE FRONT OF THE DOOR, AFTER REMOVING THE SMALL FOAM PATCH, IF PRESENT. INSPECT REMAINING PATCHES FOR PROPER COVERAGE OF HOLES. IF HOLES ARE EXPOSED, SEAL WITH SIMILAR PATCH MATERIAL OR DUCT TAPE. INSTALL THE A-PILLAR GARNISH MOLDING OVER THE FOAM BY GENTLY SPREADING LOWER END OF GARNISH WITH BOTH HANDS, AND SLIDING GARNISH OVER FOAM INSULATOR, MAKING SURE THAT THE FOAM WRAPS AROUND THE PILLAR INSIDE THE GARNISH. THE REAR DOOR FOAM INSULATOR IS INSTALLED IN A SIMILAR MANNER, EXCEPT THAT THE FOAM DOES NOT HOOK OVER THE END OF THE DOOR. RATHER, THE NOSE PIECE OF THE FOAM RESTS IN THE NOTCH IN THE DOOR END PANEL.

INSTALL THE REMAINING GARNISH MOLDING AND APPLIQUE. INSTALL A FOAM STRIP ALONG THE ENTIRE LENGTH OF THE ANGLED SURFACE ADJACENT TO THE MOUNTING SURFACE ON THE BACK OF THE APPLIQUE. USE 3M EXTERIOR DOOR FOAM WEATHERSTRIP, CATALOGUE #2104, OR EQUIVALENT, 450MM LONG. ALIGN FRONT AND REAR APPLIQUES. REPOSITION "T" FOAM PATCH AT THE TOP OF THE DIVISION POST IF IT WAS REMOVED.

INSTALL THE TRIANGLE PATCH ON THE INNER SURFACE OF THE MOLDED TRIANGLE AT THE BOTTOM OF THE DIVISION POST ON THE FRONT DOOR GLASS RUN CHANNEL (FIGURE 18). BUICKS AND PONTIACS USE THE SMALLER CHEVRON OR V-SHAPED PATCH ON EITHER SIDE OF THE VEHICLE. THE OLDSMOBILE PATCH IS TALLER AND IS UNIQUE TO EACH SIDE OF THE VEHICLE.

INSTALL "L" FOAM AT THE TOP OF THE B-PILLAR LEG OF THE GLASS RUN CHANNEL BETWEEN SEALING LIPS (FIGURE 20). CUT TWO (2) THIN STRIPS OF 3M EXTERIOR DOOR FOAM WEATHERSTRIP, CATALOGUE #2104, OR EQUIVALENT, 80MM EACH. ON VEHICLES BUILT BEFORE NOVEMBER, 1992, THREE SEALING LIPS HAVE BEEN NOTCHED TO CLEAR THE BLOW-OUT CLIP ON THE REAR DOOR B-PILLAR APPLIQUE. (ON LATER VEHICLES, ONLY TWO LIPS WERE NOTCHED). USE A STRIP OF "L" FOAM MATERIAL OR FOAM TAPE TO EXTEND THE SEAL PAST THE NOTCHED AREA.

1991 AND EARLY 1992 VEHICLES HAVE A MOLDED END AT THE BOTTOM OF THE A-PILLAR LEG OF THE FRONT GLASS RUN CHANNEL. ON LATER VEHICLES, THE CHANNEL IS SIMPLY CUT OFF AT THE BOTTOM. USING RTV OR A SIMILAR MATERIAL, SEAL THE END OF THE OPEN CHANNEL AND ANY GAP TO THE FOAM RUBBER SEAL (FIGURE 21).

INSTALL THE GLASS RUN CHANNEL, USING CARE NOT TO DAMAGE FOAM PATCHES. DO NOT STICK DOWN DOUBLE-SIDED TAPE YET. CHECK THE POSITION OF THE INNER BELT STRIP ON THE FRONT DOOR. THE EDGE OF THE SEALING LIP AT THE DIVISION POST NOTCH SHOULD TOUCH THE REAR EDGE OF THE MOLDED TRIANGLE ON THE GLASS RUN CHANNEL. IF THERE IS A GAP, IT MAY BE POSSIBLE TO SLIDE THE BELT STRIP FORWARD; OTHERWISE IT WILL BE NECESSARY TO REMOVE THE DOOR TRIM PANEL AND REPOSITION THE BELT STRIP.

IF THE UPPER PORTION OF THE FRONT DOOR APPLIQUE WAS NOT TIGHTLY SEALED TO THE GLASS AND NOISE WAS OBSERVED ALONG THE B-PILLAR, THE GLASS RUN RETAINING CHANNEL MUST BE TIGHTENED. LAY THE APPLIQUE FACE-DOWN ON A PADDED SURFACE AND TAP THE BACK OF THE CHANNEL SECTION WITH A MALLET. NOTE THAT THE UPPER END OF THE CHANNEL WILL BEND MUCH MORE EASILY THAN THE CENTER PORTION. AN ALTERNATIVE TECHNIQUE IS TO PERFORM THE ADJUSTMENT ON THE CAR WITH THE WINDOW DOWN USING A HAMMER AND A BLOCK OF WOOD WRAPPED IN A RAG. THE SEAL SHOULD BE JUST SNUG ENOUGH THAT SOME RESISTANCE IS FELT WHEN A DOLLAR BILL OR AN INDEX CARD IS SLIPPED BETWEEN THE GLASS AND THE SEAL. IF THE APPLIQUE IS TOO TIGHT, IT WILL PREVENT THE WINDOW FROM CLOSING PROPERLY AND/OR CAUSE PREMATURE WEAR OF THE SEALS. IT IS VERY EASY TO DAMAGE PARTS WHEN MAKING THIS ADJUSTMENT, SO GREAT CARE MUST BE USED. HOWEVER, A LOOSE APPLIQUE WILL CAUSE A GREAT DEAL OF WINDNOISE VERY CLOSE TO THE DRIVER'S OR PASSENGER'S EAR, SO THIS ADJUSTMENT CAN MAKE A SIGNIFICANT IMPROVEMENT IN THE WINDNOISE PERFORMANCE.

RUN THE WINDOW UP TO ENSURE PROPER OPERATION AND CHECK FOR ADEQUATE PENETRATION OF THE GLASS INTO THE SEALS AROUND THE ENTIRE PERIMETER. IF NECESSARY, REMOVE THE TRIM PAD AND READJUST THE GLASS.

IF NOISE WAS OBSERVED FROM THE REAR DOOR GLASS ALONG THE UPPER PORTION OF THE B-PILLAR AND ALONG THE TIP EDGE NEAR THE DIVISION POST, IT WILL BE BENEFICIAL TO TILT THE GLASS FORWARD SLIGHTLY. THIS IS DONE BY LOOSENING THE REAR SASH MOUNTING NUT AND SHIFTING THE REAR MOUNTING STUD TO THE TOP OF ITS HOLE. IF ADDITIONAL TILT IS NEEDED, IT WILL BE NECESSARY TO REMOVE THE SASH AND FILE THE BOTTOM OF THE FRONT HOLE. AFTER ASSEMBLY, READJUST THE GLASS, THEN SHIFT THE REAR STUD UPWARD AGAIN.

AFTER DETERMINING THAT THE WINDOW OPERATION AND GLASS SEALING ARE SATISFACTORY, HOLD THE GLASS RUN CHANNEL FIRMLY AGAINST THE DOOR FRAME AND STICK DOWN THE DOUBLE-SIDED TAPE. CLOSE THE DOOR AND CHECK FOR PROPER SEATING OF THE AUXILIARY SEALING LIP AGAINST THE A-PILLAR MOLDING AND DRIP RAIL. IF NECESSARY, LIFT THE TAPE AND REPOSITION THE CHANNEL. INSTALL THE DIVISION POST GARNISH MOLDING AND THE OUTER BELT STRIP, MAKING SURE THAT ALL CLIPS ARE ENGAGED AND THE STRIP IS FULLY SEATED ON THE DOOR.

AN ADDITIONAL SOURCE OF NOISE ON BUICKS IS WHISTLING DOOR HANDLES. THIS WILL BE HEARD AS A SINGLE TONE AT APPROXIMATELY 2500 HZ, AND MAY BE ISOLATED WITH A STETHOSCOPE BY LISTENING AT THE INTERIOR DOOR HANDLE OPENING. THE SOURCE OF THE WHISTLE IS THE LONGITUDINAL GAP BETWEEN THE DOOR HANDLE CASTING AND THE PLASTIC PORTION OF THE HANDLE, ABOVE THE PUSHBUTTON. TO ELIMINATE THE WHISTLE, HOLD THE BUTTON IN AND USE RTV TO SEAL THE GAP (FIGURE 22), USING CAUTION NOT TO OBSTRUCT THE GUIDE SLOTS FOR THE PUSHBUTTON.

C1 - BACKLITE PERIMETER LEAKS

A SUSPECTED LEAK IN THE BACKLITE URETHANE SEAL SHOULD BE CONFIRMED USING ONE OF SEVERAL STATIC TEST METHODS. AN ULTRASONIC TESTER SUCH AS J26419 OR SNAP ON AC6600 IS PREFERRED, BUT ANY METHOD THAT CAN PINPOINT THE EXACT LEAK LOCATION WILL SAVE TIME.

REPAIR METHOD:

THE RECOMMENDED METHOD FOR REPAIRING THE LEAK IS TO FLOOD THE LEAK AREA WITH A URETHANE SEALANT. COVER THE AREA SURROUNDING THE LEAK SUFFICIENTLY TO AVOID CREATING A NEW LEAK PATH BETWEEN THE LEAK AND THE NEWLY APPLIED SEALANT. GIVE THE SEALANT SUFFICIENT TIME TO CURE TO AVOID BLOWING A NEW HOLE THROUGH THE SEALANT.

1991-93 "C" AND 1993 "H" FLO-THRU VENTILATION DESCRIPTION OF OPERATION (SEE FIGURE 23)

THE AIR EXITING THE REAR DOOR LOCK PILLAR BAFFLE CAN BE FELT COMING OUT THE GAP BETWEEN THE DOOR AND THE LOCK PILLAR. IT IS POSSIBLE THIS AIR MOVEMENT CAN ALSO BE HEARD. THIS SYSTEM CAN MOVE APPROXIMATELY 300CFM, SO THE VOLUME OF AIR FELT IS CONSIDERABLE.

PARTS ARE EXPECTED TO BE AVAILABLE ON MAY 23, 1994.

WARRANTY INFORMATION:

FOR VEHICLES REPAIRED UNDER WARRANTY, USE:

LABOR OPERATION NO.: T5303 1.1

ROAD TEST AND DIAGNOSE WINDNOISE (INC. 2ND PERSON ASSISTANCE AND TAPE SUSPECT AREAS) SELECT THE APPROPRIATE ADD CONDITION FROM THE LIST BELOW FOR THE REPAIR(S) MADE

ADD: TO COMPLETE CHART A1............................ .5 TO COMPLETE CHART A2............................ .3 TO COMPLETE CHART A3 ONE SIDE..................................... .2 BOTH SIDES................................... .3 TO COMPLETE CHART A4 ADJUST RUN CHANNEL ONLY ONE SIDE..................................... .3 BOTH SIDES................................... .6 ADJUST RUN CHANNEL AND DOOR POSITION ONE.......................................... .5 BOTH......................................... 1.0 TO COMPLETE CHART A5 ONE SIDE..................................... .2 BOTH SIDES................................... .3 TO COMPLETE CHART B1 ONE DOOR..................................... .1 BOTH DOORS................................... .2 TO COMPLETE CHART B2 TO INSERT FOAM ONLY ONE DOOR..................................... .1 ADD EACH ADDITIONAL DOOR..................... .1 TO CORRECT MIRROR PATCH ONE DOOR..................................... .6 BOTH DOORS................................... 1.2 TO COMPLETE CHART B3 ONE FRONT DOOR............................... .5 BOTH FRONT DOORS............................. 1.0 ONE REAR DOOR................................ .4 BOTH REAR DOORS.............................. .8 TO COMPLETE CHART B4 ONE DOOR..................................... .1 BOTH DOORS................................... .2 TO COMPLETE CHART B5 TO ADJUST PRIMARY WEATHERSEAL ONE.......................................... .3 EACH ADDITIONAL.............................. .3 TO ADJUST PRIMARY WEATHERSEAL AND DOOR POSITION ONE.......................................... .5 EACH ADDITIONAL.............................. .5 TO COMPLETE CHART B6 INSTALL WINDNOISE REDUCTION KIT, 1 FRONT DOOR .8 BOTH FRONT DOORS............................. 1.6 ADJUST FRONT WINDOW, IN/BELT STRIP, APPLIQUE EACH FRONT DOOR.............................. .4 INSTALL WINDNOISE REDUCTION KIT, 1 REAR DOOR 1.0 BOTH REAR DOORS.............................. 2.0 ADJUST REAR WINDOW, IN/BELT STRIP, APPLIQUE EACH REAR DOOR............................... .1 TO COMPLETE CHART C1............................ .2

FIGURES: 23 ATTACHMENTS: 1

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 1994 GENERAL MOTORS CORPORATION. ALL RIGHTS RESERVED.