Reoccurring Glass Panel Rattles and/or Looseness

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.
Reoccurring Glass Panel Rattles and/or Looseness

When glass panel rattles or looseness reoccur 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 - in October, 1988 the lifter arm guide pin slot was reduced to prevent looseness of the glass panel linkage when the glass is closed.

On vehicles built prior to October, 1989, replace the lifter arms using the part numbers listed below. Reference 1990 Service Information Manual, Section 10-9, for removal and installation procedure.

Lifter Arm P/N

Left 12504123
Right 12504124

Parts are currently available from GMSPO.

To verify parts stock or car installed parts 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 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:

Figure 2 - Sunroof Track Pivot Plates:

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 2 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" (5 mm) drill to remove only the head of the rivet, two rivets each side. Use a 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