File in Section:
Bulletin No.:

Service Bulletin

Date:

16-NA-370
February, 2018

TECHNICAL
Subject:

Sunroof Rattle, Creak, Tick and/or Double Click Noise During Operation

Brand:

Model:

Cadillac

CT6

Model Year:

VIN:

from

to

2016

2017

from

Engine:

Transmission:

All

All

to

Involved Region or Country

North America, Japan, Korea, Russian Federation, Europe, China, Middle East, Israel

Additional Options (RPO)

Equipped with Sunroof (RPO C3U)

Condition

Some customers may comment on hearing any of the following noises during vehicle
operation:
• Rattle
• Creak
• Tick
• Double Click (usually heard when closing the sunroof)

Cause

The cause of the condition may be attributed to part to part contact, such as any of the
following:
• Metal to aluminum contact of the rear glass trough to the guide rail.
• Metal to metal contact of the mechanism tab to the mechanism curve on the window
slider.
• Metal to aluminum contact at outboard left or right sunroof housing rivet locations.
• The sunroof window inner middle seals may be an early first design, or a new second
design seal may be mis-positioned/rolled.
• Excessive material on the sunroof mechanism rubber isolator may be allowing double
contact when the sunroof window travels.

Correction

Service Procedure

A combination of different repairs, up to total of four,
could be necessary depending on specific breakpoints
of part changes and inspection of proper location of the
sunroof window inner middle seals. Verify the
condition(s) and follow the steps of the Service
Procedure below to complete the appropriate repair(s).

4622186
Copyright 2018 General Motors LLC. All Rights Reserved.

Page 2

February, 2018

Bulletin No.: 16-NA-370

Note: The right side tab is shown circled in the graphic
above. The front sunroof window was removed for
illustration purposes only.
1. Open the front sunroof window enough to gain
access to the tab which hangs down from the
mechanism bracket, on each side of the sunroof.
They are located approximately 30.5 mm (1.2 in)
rearward of the front window screw.

4622189

2. Apply GM - ACDelco Super Lube®* P/N 12371287
(in Canada, use P/N 10953437), or equivalent, to
the top and bottom horizontal surfaces of the tabs
on BOTH the left and right sides.
• For vehicles built prior to July 1, 2016,
continue to step #3.
• For vehicles built July 1, 2016 or after, move
ahead to step #7.

4622191

3. Locate the small “tail” extrusion on the rubber
isolator on one side of the sunroof.

Bulletin No.: 16-NA-370

February, 2018

4622194

4. Using sharp nosed cutter/shears, or suitable tool,
trim off the ‘tail” as flush to the surface as possible.
The trimmed piece should stick to the shears for
extraction.

Page 3

4622199

7. For earlier built vehicles, it will be necessary to
remove four outboard rivets, two each side, from
the center frame of the sun housing.
• For vehicles built June 17, 2016 and prior,
continue to step #7.1.
• For vehicles built after June 17, 2016, move
ahead to step #15.

4624462

5. Examine isolator to see if further trimming is
required, and if so, go straight down and trim
further. A flush trimmed isolator is shown circled in
the graphic above.
6. Repeat steps 3-5 on the opposite side.

4622202

7.1. Remove the sunroof housing assembly (1).
Refer to Sunroof Housing Replacement (With
C3U) in SI.
7.2. Place housing on a protected, suitable table/
bench with the underside facing up.

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February, 2018

4622207

7.3. Locate the two center, outboard rivets (1) on
one side of the housing.

Bulletin No.: 16-NA-370

4622214

7.5. Using a carbide die grinder bit, or equivalent
tool, carefully grind off the head of the rivet at
both locations.
7.6. Punch out the rivets from the two locations.
7.7. Repeat steps 7.3-7.6 on the opposite side.

4622210

7.4. Install vise-grips or a suitable tool, to the
housing to hold the metal frame layers in
position, while grinding the rivets.

4622218

8. Cut four pieces of *Kent Automotive BRS Tape P/N
KT13486, or equivalent flocking tape; two pieces
approximately 30 x 45 mm (1.2 x 1.8 in) (1) and two
approximately 30 mm x 90 mm (1.2 x 3.6 in) (2).

Bulletin No.: 16-NA-370

February, 2018

4622222

9. As shown in the graphic above, apply the four
pieces of flocking tape between the metal flanges
of the sunroof frame at the four removed rivet
locations. The smaller pieces forward, the larger
pieces rearward.
10. Flip over the sunroof housing so you have access
to the top side.

4622225

Note: To improve performance, a more robust second
design of the sunroof inner middle seal has been
implemented. The first graphic above shows the
difference between the first (1) and second (2) design
level.

Page 5

Page 6

February, 2018

Bulletin No.: 16-NA-370

4622229

Note: The second graphic shows an illustration and
cross-section of the correct positioning of the second
design seal (1). The added portion of the seal (3) is
intended to cap-over the guide flange (2) and isolate
the drain channel from contact with the guide flange.

4622231

4622225

11. Inspect the sunroof window inner middle seals on
both sides of the sunroof. We first want to ensure
the vehicle has the new second design seals, and
if so, want to make sure the seals are properly
positioned.
• For vehicles equipped with first design seals
(1), continue to step #12.
• For vehicles equipped with second design
seals (2):

⇒ Inspect the seals for evidence of them being
mis-positioned, or rolled out of position on either or
both sides. If this condition exists and the guide
flange is exposed, there will likely be corrosion
evident (shown circled above), due to the metal to
metal contact of drain channel to the guide. If
exposure of the guide flange or corrosion is evident,
continue to step #12.

Bulletin No.: 16-NA-370

February, 2018

4622234

⇒ The graphic above shows examples of proper seal
installation. Some slight roll of the seal is
acceptable as long as the drain channel is
completely isolated from the guide flange. If they
are properly positioned on both sides, move ahead
to step #13.

4622238

12. For vehicles with first design seals, replace both
sides; for second design seals, replace only the
affected side. Refer to Sunroof Window Seal
Replacement (Inner Middle Seal With C3U) in SI.
13. Reinstall the sunroof housing assembly. Refer to
Sunroof Housing Replacement (With C3U) in SI.
14. Move ahead to step #17.

Page 7

4622225

Note: To improve performance, a more robust second
design of the sunroof inner middle seal has been
implemented. The first graphic above shows the
difference between the first (1) and second (2) design
level.

Page 8

February, 2018

Bulletin No.: 16-NA-370

4622229

Note: The second graphic shows an illustration and
cross-section of the correct positioning of the second
design seal (1). The added portion of the seal (3) is
intended to cap-over the guide flange (2) and isolate
the drain channel from contact with the guide flange.

seals (2):

4622231

4622225

15. Open the front sunroof window and inspect the
sunroof window inner middle seals on both sides of
the sunroof. We first want to ensure the vehicle has
the new second design seals, and if so, want to
make sure the seals are properly positioned.
• For vehicles equipped with first design seals
(1), continue to step #16.
• For vehicles equipped with second design

⇒ Inspect the seals for evidence of them being
mis-positioned, or rolled out of position on either or
both sides. If this condition exists and the guide
flange is exposed, there will likely be corrosion
evident (shown circled above), due to the metal to
metal contact of drain channel to the guide. If
exposure of the guide flange or corrosion is evident,
continue to step #16.

Bulletin No.: 16-NA-370

February, 2018

Page 9

4622234

⇒ The graphic above shows examples of proper seal
installation. Some slight roll of the seal is
acceptable as long as the drain channel is
completely isolated from the guide flange. If they
are properly positioned on both sides, move ahead
to step #17.

4622244

16. For vehicles with first design seals, replace both
sides; for second design seals, replace only the
affected side. Refer to Sunroof Window Seal
Replacement (Inner Middle Seal With C3U) in SI.
17. Verify noise conditions have been eliminated and
proper operation of sunroof.
*We believe this source and their products to be
reliable. There may be additional manufacturers of
such products/materials. General Motors does not
endorse, indicate any preference for, or assume any
responsibility for the products or material from this firm
or for any such items that may be available from other
sources.

Parts Information
Order BRS Tape from Kent Automotive at
1-888-YES-KENT, or online at
www.kent-automotive.com.
Description

Part
Number

Qty

SEAL-SUN RF WDO

84114679

1, if
necessary

SEAL-SUN RF WDO

84114680

1, if
necessary

Kent Automotive BRS Tape

KT13486

4 pieces, if
necessary

Page 10

February, 2018

Bulletin No.: 16-NA-370

Warranty Information
For vehicles repaired under the Bumper-to-Bumper
coverage (Canada Base Warranty coverage), use the
following labor operation. Reference the Applicable
Warranties section of Investigate Vehicle History (IVH)
for coverage information.
Labor
Operation

Description

Labor Time

6080198*

Lubricate Sunroof
Mechanism Tabs

0.2 hr

Add

Trim Isolator Tails

0.1 hr

Add

Install Second Design
Seals, Only

1.4 hrs

Add

Remove Outboard Sunroof
Housing Rivets (Inc. Install
Seal(s))

7.0 hrs

*This is a unique Labor Operation for Bulletin use only.

Version

2

Modified

February 16, 2018 – Updated the coverage statement and some Labor Times under
Warranty Information.

GM bulletins are intended for use by professional technicians, NOT a "do-it-yourselfer". They are written to inform these
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 your GM dealer for information on whether your vehicle may benefit from the
information.

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