GM Service Manual Online
For 1990-2009 cars only

WEBESTO SUNROOF REPAIRS

REVISION # 1 THIS BULLETIN HAS BEEN REVISED TO INCLUDE 1990 MODEL YEAR AND UPDATED REPAIR INFORMATION . THIS BULLETIN CANCELS AND REPLACES BULLETIN T-89-57 (CORPORATE BULLETIN 811526R) ISSUED IN JANUARY, 1989

REVISION # 2 THIS BULLETIN IS BEING REVISED TO INCLUDE 1991 AND 1992 MODEL YEARS, AND UPDATE A PART NUMBER.

REVISION: 12/15/94

THIS BULLETIN IS BEING REVISED TO ADD THE G MODEL, INCLUDE 1993 THROUGH 1995 MODEL YEARS AND UPDATE A PART NUMBER.

PREVIOUS DIVISIONAL PUBLICATION NUMBERS WERE: BUICK 90-10-22 CADILLAC T-90-58 GM OF CANADA 90-2-160 OLDSMOBILE 90-T-104 PONTIAC 90-10-24 ----------------------------------------------------------------------

SUBJECT: INFORMATION ON WEBASTO SUNROOF REPAIRS

MODELS: 1988-95 BUICK CENTURY, LESABRE, PARK AVENUE 1988-90 BUICK ELECTRA 1988-93 BUICK RIVERIA 1995 BUICK RIVERIA 1988-92 CADILLAC BROUGHAM 1988-95 CADILLAC DEVILLE, ELDORADO, FLEETWOOD, SEVILLE 1994-95 CADILLAC CONCOURS 1988-92 OLDSMOBILE TORONADO, TROFEO 1988-95 OLDSMOBILE CUTLASS CIERA, EIGHTY EIGHT, NINETY EIGHT 1995 OLSMOBILE AURORA 1988-95 PONTIAC BONNEVILLE

FOR GENERAL SERVICE INFORMATION AND PROCEDURES REFER TO THE APPROPRIATE SERVICE INFORMATION MANUAL, SECTION 10. A FACTORY-INSTALLED SUNROOF CAN BE IDENTIFIED BY CF5 ON THE SERVICE PARTS IDENTIFICATION LABEL.

WINDNOISE

GLASS PANEL POSITION

PROPER GLASS PANEL POSITION IS LOW IN THE FRONT AND HIGH IN THE REAR. THE PANEL SHOULD BE ADJUSTED TO 1-1.5MM LOW IN FRONT, 1- 1.5MM HIGH AT THE CENTER, REAR. PROPER PANEL ADJUSTMENT HAS BEEN FOUND TO ELIMINATE MOST WINDNOISE COMMENTS.

IF ADJUSTMENT IS NECESSARY, USE LABOR OPERATION B2720 AT .5 HOUR.

GLASS WEATHERSTRIP

IF PROPER GLASS PANEL ADJUSTMENT DOES NOT ELIMINATE THE WINDNOISE AT THE SUNROOF GLASS, CONTINUE WITH THE FOLLOWING:

1. CHECK SEAL-TO-ROOF GAP BY SLIDING A THIN CARD (BUSINESS CARDS WORK WELL) ALONG EACH EDGE OF THE GLASS PANEL BETWEEN THE SEALING SURFACES. SOME FRICTION SHOULD BE PRESENT, ALTHOUGH THE CARD SHOULD SLIDE RATHER EASILY. IF NO GAPS ARE NOTED, INVESTIGATE SOURCES OF WINDNOISE OTHER THAN THE SUNROOF. LOOK FOR OTHER KNOWN CAUSES OR BULLETINS WHICH MAY APPLY.

2. IF A SMALL GAP IS NOTED ALONG THE FRONT OF THE GLASS PANEL, ADJUST THE PANEL FORWARD AS FAR AS POSSIBLE. RECHECK THE GAP TO BE SURE A PROPER SEAL IS MAINTAINED AT THE REAR.

3. IF THE VEHICLE IS EQUIPPED WITH A FULL VINYL ROOF, INSPECT TO BE SURE THE VINYL TOP RETAINER RING IS ASSEMBLED PROPERLY. IF THE TRIM RING APPEARS TO BE ASSEMBLED PROPERLY (STRAIGHT; DOES NOT APPEAR WAVY), GO TO STEP 4.

IF INCONSISTENT GAPS WERE NOTED IN STEP 1 AND THE RETAINER RING APPEARS TO BE WAVY, THE VINYL TOP MAY NOT BE TRIMMED CORRECTLY. REMOVE THE RETAINER AND TRIM THE VINYL AWAY FROM ALL RIVET AREAS TO ALLOW THE RETAINER RING TO LAY FLAT. IF A VINYL TOP SEAM RUNS INTO THE OPENING, ENSURE THAT THE SEAM AREA IS TRIMMED AWAY TO PROVIDE A FLAT MOUNTING AREA FOR THE RETAINER RING. REFER TO FIGURE 1.

4. WITH SUNROOF USAGE OVER TIME, A GAP MAY DEVELOP ALONG THE BACK OF THE GLASS PANEL BETWEEN THE SEAL AND HOUSING OR TRIM RING DUE TO CRUSHING OF THE SEAL. CRUSHING OF THE FRONT EDGE, COMBINED WITH THE TENDENCY OF THE SEAL MATERIAL TO TAKE A SET, ALLOWS THE GLASS PANEL TO TRAVEL FURTHER FORWARD IN THE OPENING RESULTING IN THE REAR GAP. IF THIS IS THE CASE, SEAL REPLACEMENT IS REQUIRED. FOLLOW THE WEATHERSTRIP REPLACEMENT PROCEDURE SPECIFIED IN THE SERVICE INFORMATION MANUAL NOTING THE SPECIAL PROCEDURES BELOW FOR ASSEMBLY AND ADJUSTMENT OF THE GLASS PANEL AFTER SEAL REPLACEMENT.

GLASS PANEL SEAL PART NUMBERS ARE AS FOLLOWS:

WITHOUT FULL VINYL: P/N 12536412 - HAS INTERNAL REINFORCEMENT

WITH FULL VINYL: P/N 12393333

P/N 12536412 HAS AN INTERNAL REINFORCEMENT WHICH MUST BE CENTERED AT THE FRONT OF THE GLASS PANEL. THIS SEAL WAS IMPLEMENTED INTO PRODUCTION ON 1990 VEHICLES IN SEPTEMBER ON ELDORADOS AND SEVILLES, AND NOVEMBER ON DEVILLES AND FLEETWOODS. P/N 12393333 IS A SMALLER SEAL AND DOES NOT HAVE A REINFORCEMENT DUE TO THE OPENING RESTRICTIONS RESULTING FROM THE VINYL TOP AND TRIM RING. P/N 12536412 CANNOT BE USED ON A VEHICLE WITH A VINYL TOP.

NOTE: THE SEAL INTERNAL REINFORCEMENT SHOULD BE CENTERED AT THE FRONT OF THE GLASS PANEL.

PARTS ARE CURRENTLY AVAILABLE FROM GMSPO.

FOR WARRANTY PURPOSES USE LABOR OPERATIONS C1440 (WEATHER SEAL REPLACEMENT) AT .8 HOUR.

NEW WEATHERSTRIP SPECIAL INSTALLATION PROCEDURE - WITH A NEW SEAL, THE PANEL MAY INITIALLY STICK WHEN MOVING FROM THE CLOSED POSITION UP INTO VENT OR DOWN TO SLIDE TO THE REAR. TO ENSURE CORRECT HEIGHT ADJUSTMENTS USE THE FOLLOWING PROCEDURE:

1. FOR EASIER ACCESS TO THE GLASS PANEL MOUNTING SCREWS, START THE SCREWS WITH THE PANEL IN THE VENTED POSITION. DO NOT TIGHTEN ANY OF THE SCREWS WITH THE PANEL VENTED. THIS CAN CAUSE THE PANEL TO BE TOO FAR FORWARD IN THE OPENING.

2. CLOSE THE PANEL. ADJUST THE GLASS PANEL POSITION AS DESCRIBED IN THE SERVICE INFORMATION MANUAL AND TIGHTEN THE GLASS PANEL MOUNTING SCREWS.

3. OPERATE SUNROOF TO FULLY BACK, OPEN POSITION. BRING TO CLOSED POSITION HOLDING SWITCH UNTIL MOTOR STALLS.

4. TAP ROOF PANEL AT REAR TO ALLOW GLASS TO FIND NATURAL SETTING. READJUST AS NECESSARY.

5. ALLOW THE NEW SEAL TO SET OVERNIGHT WITH THE GLASS POSITIONED AS DESCRIBED ABOVE. IF THE PANEL CONTINUES TO HANG UP AT THE REAR, SLIDE THE SHAFT OF A SCREWDRIVER (OR SIMILAR TOOL) ALONG THE REAR OF THE SEAL. THIS SHOULD ALLOW CONTINUED PROPER OPERATION.

NOISY/RATTLES

COMMENTS OF LIFTER ARMS RATTLE, GLASS PANEL RATTLES, EXCESSIVE VERTICAL PLAY AT REAR OF GLASS

RATTLES AND LOOSENESS AT THE REAR OF THE GLASS PANEL WHEN IN THE CLOSED POSITION MAY BE CAUSED BY LOOSENESS IN THE LIFTER ARM LINKAGES. THIS CONDITION CAN BE CAUSED BY MISPOSITIONED OR IMPROPERLY BENT GLASS PANEL MOUNTING BRACKETS. IF PUSHING UP ON THE REAR OF THE GLASS PANEL RESULTS IN MORE THAN 1/8" OF MOVEMENT OR CAUSES A "CLUNKING" NOISE, USE THE FOLLOWING PROCEDURE TO REDUCE GLASS PANEL MOVEMENT:

1. REMOVE THE GLASS PANEL AND TURN UPSIDE DOWN ON A CLEAN, NON-ABRASIVE SURFACE.

2. USING PLIERS OR CHANNEL LOCKS, BEND THE SIX PANEL ATTACHING BRACKETS SO THEY ARE 90 DEGREES TO THE GLASS PANEL SURFACE. REFER TO FIGURE 2.

3. REINSTALL AND ADJUST THE GLASS PANEL.

OPERATE THE SUNROOF TO ENSURE PROPER FUNCTIONING. IF THE MOUNTING BRACKETS ARE BENT TOO FAR DURING THE ABOVE PROCEDURE, TWO CONDITIONS MAY OCCUR: 1) THE SUNROOF MAY OPERATE SLOWLY DUE TO INCREASED FRICTION; 2) THE TRACK MAY INTERFERE WITH THE LIFTER ARMS WHEN CLOSING FROM VENT POSITION CAUSING A LOUD POPPING NOISE. TO REPAIR THESE CONDITIONS USE THE FOLLOWING PROCEDURE:

1. READJUST THE CENTER MOUNTING TABS SLIGHTLY OUTBOARD. THIS CAN BE ACCOMPLISHED WITHOUT REMOVING THE GLASS BY APPLYING FORCE TO THE SCREW HEAD FROM THE INSIDE. POSITION A DULL PUNCH ON THE SCREW HEAD AND TAP WITH A HAMMER. READJUSTMENT WILL ELIMINATE THE INTERFERENCE CONDITION AND SHOULD RELIEVE SOME OF THE FRICTION.

2. OPERATE THE SUNROOF TO VERIFY THAT THE CONDITION HAS BEEN ELIMINATED.

3. IF THE GLASS PANEL CONTINUES TO MOVE SLOWLY, MAKE A SLIGHT OUTBOARD ADJUSTMENT TO THE FRONT AND REAR MOUNTING TABS ON EACH SIDE OF THE PANEL.

FOR WARRANTY PURPOSES USE LABOR OPERATION T6349 AT .5 HOUR.

RECURRING GLASS PANEL RATTLES AND/OR LOOSENESS

WHEN GLASS PANEL RATTLES OR LOOSENESS RECURS OVER TIME, PERFORM THE FOLLOWING STEPS ONLY ON THE VEHICLES SPECIFIED FOR EACH PROCEDURE. BOTH OF THE FOLLOWING CORRECTIONS HAVE BEEN IMPLEMENTED INTO PRODUCTION VEHICLES DURING THE MONTHS NOTED. THESE CHANGES HAVE BEEN MADE TO LIMIT MOVEMENT OF THE LIFTER ARM WHEN THE GLASS PANEL IS CLOSED.

VEHICLES BUILT PRIOR TO OCTOBER, 1989 WITHOUT VINYL TOPS - IN OCTOBER, 1989 THE LIFTER ARM GUIDE PIN SLOT WAS REDUCED TO PREVENT LOOSENESS OF THE GLASS PANEL LINKAGE WHEN THE GLASS IS CLOSED. THE NEW LIFTER ARMS WERE IMPLEMENTED ON SEVILLES AT VIN LU803080 AND ON ELDORADOS AT VIN LU604077. OLDSMOBILE TORONADOS VIN 302169 AND BUICK RIVIERAS VIN 403851.

ON VEHICLES BUILT PRIOR TO THE BREAKPOINT, REPLACE THE LIFTER ARMS USING THE PART NUMBERS LISTED BELOW. REFERENCE THE APPROPRIATE SERVICE INFORMATION MANUAL, SECTION 10-9, FOR REMOVAL AND INSTALLATION PROCEDURE.

LIFTER ARM P/N

LEFT 12504123 RIGHT 12504124

DO NOT USE THESE LIFTER ARMS ON VEHICLES WITH FULL VINYL TOPS. THESE ARMS WILL NOT PROVIDE ADEQUATE ADJUSTMENT FOR PROPER GLASS PANEL ALIGNMENT TO THE VINYL TOP RETAINER RING. PROPER ADJUSTMENT OF THE GLASS PANEL AND MOUNTING TABS SHOULD BE SUFFICIENT TO ELIMINATE RATTLES ON VEHICLES WITH VINYL TOPS.

TO VERIFY PARTS STOCK FOR THE UPDATED LIFTER ARMS, LOOK FOR THE NUMBER STAMPED ON THE INSIDE SECTION OF THE ARM. NEW LIFTER ARMS WILL BE STAMPED 1186-A-3100 A.B. OR 1186-A-3101 A.B.

FOR WARRANTY PURPOSES USE LABOR OPERATION T6428 AT .6 HOUR.

VEHICLES BUILT PRIOR TO DECEMBER, 1988 - REPLACE THE LIFTER ARM PIVOT PLATES WITH THICKER PARTS. THIS CHANGE WAS IMPLEMENTED INTO PRODUCTION IN EARLY DECEMBER, 1988. PARTS REQUIREMENTS ARE AS FOLLOWS:

PIVOT PLATE KIT, P/N 12500028 - INCLUDES RH AND LH PIVOT PLATES AND SIX RIVETS (FOUR BLACK, TWO SILVER). ONLY THE BLACK RIVETS ARE USED.

REPLACE THE PIVOT PLATES WITH NEW, THICKER PIVOT PLATES USING THE FOLLOWING PROCEDURE:

1. OPEN THE GLASS PANEL TO THE FULL BACK POSITION.

2. REMOVE HEADLINER TRIM LACE AND PULL HEADLINER LOOSE AT THE SIDE AND BACK OF THE SUNROOF OPENING IN THE PIVOT PLATE LOCATIONS. REFER TO FIGURE 3 TO LOCATE PIVOT PLATES.

3. TAPE UNDERSIDE OF HOUSING TO CONTACT RIVET SLUG. PLACE TAPE OVER CABLE OPENING IN TRACK TO PREVENT DRILL SHAVINGS FROM ENTERING TRACK.

4. USE A 7/32" (5MM) DRILL TO REMOVE ONLY THE HEAD OF THE RIVET, TWO RIVETS EACH SIDE. USE CAUTION NOT TO DRILL THROUGH THE HOUSING OR HEADLINER. DRILLING THROUGH THE HOUSING MAY MAKE THE HOLE TOO LARGE FOR THE RIVETS SUPPLIED IN THE KIT.

5. CAREFULLY KNOCK OUT THE RIVET SLUGS AND REMOVE TAPE FROM UNDERSIDE OF HOUSING. REMOVE METAL SHAVINGS AND TAPE FROM TOP OF TRACKS. USE OF AN AIR HOSE TO BLOW THE DRILL SHAVINGS FROM THE HOUSING IS NOT RECOMMENDED AS SOME SHAVINGS MAY BE BLOWN INTO THE CABLE TRACK.

6. REMOVE TWO PIVOT PLATES BY PRYING UP TO RELEASE PLATE FROM THE TRACK.

7. POSITION THE NEW PIVOT PLATE (FROM KIT, P/N 12500028) ONTO THE TRACK LINING UP THE RIVET HOLES. THE PLATES ARE IDENTIFIED AS RIGHT-HAND (RH) OR LEFT-HAND (LH) ON THE BOTTOM SIDE. TAP THE PLATE WITH A HAMMER TO SEAT IT OVER THE RAISED STAKING AREA ON THE TRACK. ENSURE THAT THE PLATE IS FLUSH TO THE TRACK SURFACE PRIOR TO RIVETING.

8. SECURE THE TWO PIVOT PLATES USING THE FOUR BLACK RIVETS SUPPLIED IN THE KIT.

9. REINSTALL HEADLINER AND TRIM LACE.

FOR WARRANTY PURPOSES USE LABOR OPERATION T6429 AT .6 HOUR.

ISOLATION OF SUNSHADE, AIR DEFLECTOR, SHIELD

TO ISOLATE COMPONENTS AND ELIMINATE RATTLES IN THE REST OF THE SUNROOF ASSEMBLY, COMPLETE ALL OF THE FOLLOWING STEPS ON 1988 AND 1989 VEHICLES. ADD LOOP MATERIAL (SOFT LOOP HALF OF HOOK-AND-LOOP FASTENER SYSTEM, SUCH AS VELCRO OR SCOTCHMATE HOOK AND LOOP FASTENER, 3M P/N 06480) IN THE FOLLOWING LOCATIONS AS REQUIRED:

1. REMOVE SUNSHADE. OPEN GLASS PANEL PART WAY.

2. ADD LOOP MATERIAL (40MM LONG) AT THE FRONT OF THE GLASS PANEL ON THE UNDERSIDE. REFER TO FIGURE 4 FOR LOCATIONS. THIS PREVENTS AIR DEFLECTOR RATTLES AGAINST THE BOTTOM OF THE GLASS PANEL.

3. ADD A SMALL PAD (10MM) OF LOOP MATERIAL AT THE TOP FRONT CORNERS OF THE TRACK. LOCATE PAD SO DEFLECTOR RESTS ON IT WHEN CLOSED.

4. ADD LOOP MATERIAL, APPROXIMATELY 70MM LONG, ON THE TOP (BACK SIDE) OF THE SUNSHADE IN THE AREA OF THE REINFORCEMENT. REFER TO FIGURE 5 FOR LOCATIONS.

5. ADD ONE PIECE OF LOOP MATERIAL AT THE REAR OF THE SUNSHADE, APPROXIMATELY 50MM LONG, WRAPPED AROUND THE EDGE AT THE CENTER.

6. REINSTALL SUNSHADE.

FOR WARRANTY PURPOSES USE LABOR OPERATION T6345 AT .6 HOUR (1988 AND 1989 VEHICLES ONLY).

SUNSHADE "TICKING" NOISE

SOME SUNSHADES ON 1988 THROUGH EARLY 1990 MAY EXHIBIT A "TICKING" NOISE WHEN TRAVELING OVER BUMPS OR DUE TO ROAD VIBRATIONS. THIS SOUND MAY BE CAUSED BY A LOOSE ATTACHMENT OF THE SUNSHADE REINFORCEMENT.

TO DETERMINE IF THE SUNSHADE IS THE CAUSE OF SUCH A NOISE, CAREFULLY REMOVE IT FROM THE VEHICLE. HOLDING THE SUNSHADE ON EITHER SIDE, GENTLY TWIST BACK AND FORTH WHILE LISTENING FOR THE SOUND AT THE REAR OF THE REINFORCEMENT. IF A "TICKING" SOUND IS HEARD, PERFORM THE FOLLOWING PROCEDURE:

1. PLACE THE SUNSHADE UPSIDE DOWN ON A CLEAN SURFACE.

2. USING A CHISEL AND A HAMMER, RESTRIKE THE 12 TOGGLE LOCKS LOCATED AT THE SIDES AND ALONG THE BACK OF THE REINFORCEMENT. STRIKE EACH TOGGLE AREA TWICE, IN AN "X" PATTERN, AS SHOWN IN FIGURE 6.

3. APPLY A SMALL BEAD OF STANDARD, BLACK WEATHERSTRIP ADHESIVE ALONG THE REAR EDGE OF THE REINFORCEMENT.

FOR WARRANTY PURPOSES USE LABOR OPERATION T6430 AT .2 HOUR. IF THE ABOVE REWORK DOES NOT ELIMINATE THE TICKING NOISE, REPLACE THE SUNSHADE USING LABOR OPERATION B2900 AT .2 HOUR.

NOTE: A NEW SUNSHADE WITH A WELDED REINFORCEMENT WAS IMPLEMENTED IN PRODUCTION IN OCTOBER, 1989. WELDED SUNSHADES ARE EASILY IDENTIFIED DUE TO THE LACK OF THE TOGGLE LOCK "BUMPS" AROUND THE REINFORCEMENT.

TRIM LACE, LOOSE/PULLS OUT OF CORNERS/SHORT

LACE SHORT (1988-1989 MODELS)

IF THE SUNROOF OPENING TRIM LACE APPEARS SHORT OR SHRUNK, REPLACE THE LACE. A WIRE INSERT HAS BEEN ADDED TO THE TRIM LACE TO HELP PREVENT STRETCHING/SHRINKAGE. THIS WIRE WAS ADDED TO PRODUCTION PARTS DURING THE 1989 MODEL YEAR. REFER TO THE PARTS CATALOG, SECTION 14.650, FOR ORDERING INFORMATION.

FOR WARRANTY PURPOSES USE LABOR OPERATION B2860 AT .2 HOUR FOR LACE REPLACEMENT ONLY.

LACE LOOSE/FALLS OUT

IF THE LACE WILL NOT STAY IN PLACE:

1. REMOVE LACE, PULL HEADLINING MATERIAL OUT OF RETAINER.

2. USING PLIERS, SQUEEZE RETAINER TOGETHER ALL AROUND WITH A 2- 3MM GAP RESULTING. REFER TO FIGURE 7.

3. REINSTALL HEADLINING AND TRIM LACE LOCATING THE LACE SEAM AT THE LEFT SIDE OF THE OPENING, ABOVE THE DRIVER. ENSURE THAT THE TRIM LACE IS PRESSED FULLY INTO THE RETAINER, PAYING SPECIAL ATTENTION TO THE CORNERS, PRIOR TO CUTTING TO SIZE.

PARTS ARE CURRENTLY AVAILABLE FROM GMSPO.

FOR WARRANTY PURPOSES USE LABOR OPERATION T6346 AT .3 HOUR (1988- 1989 MODELS ONLY).

FIGURES: 7


Object Number: 84424  Size: FS


Object Number: 84915  Size: FS


Object Number: 85615  Size: MF


Object Number: 94517  Size: MF


Object Number: 94516  Size: MF


Object Number: 84914  Size: FS


Object Number: 84423  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.

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