60-157

Roof Noise, M2 and 108SD/114SD Day Cabs
FLA COE
FLB COE
FLD Conventional
Business Class
FLC 112 Conventional

Century Class Conventional
Argosy COE
Cargo
Columbia

Freightliner
Service Bulletin

122SD and Coronado
> Business Class M2
Cascadia
> 108SD/114SD

Description of Revisions: This bulletin replaces the version dated
March 2015. A new roof bow is available and the procedure is
updated.

General Information
On some M2 and 108SD/114SD day cab vehicles, a popping or "oil-canning" noise may be heard from the roof.
Typically this is a problem only on vehicles with a tall box-van body mounted directly behind the cab, with no
roof deflector or fairing.
The installation of an additional roof bow spanning the space between the two existing bows will minimize the
noises from the roof. If there is a complaint of the described noises coming from the roof, use the instructions in
this bulletin to install the roof bow and to add sealant between the roof bows and the roof skin.

Parts
Parts are available through the PDCs. See Table 1. Dow® Great Stuff™ Multipurpose Black Insulating Foam
Sealant can be purchased locally.

Part Number
18-44736-001

Parts Required
Description
BOW—ROOF, CENTER

Qty.
1

Table 1, Parts Required

Procedure
1. Park the vehicle on a level surface, shut down the engine, and set the parking brake. Chock the tires.
2. Drain the air tanks.
3. Disconnect the batteries.
4. Remove the passenger seat to allow enough space to remove the headliner from the cab. See the vehicle
workshop manual, Group 91.
5. Remove all items from the overhead storage bins (if equipped), then pull out the storage bins from the
overhead console.
6. Remove the overhead instrument panel surrounds (if equipped).
7. Remove the A-pillar covers, as follows:
7.1

Remove the passenger-side grab handle by removing the screws that attach it to the A-pillar.

7.2

Remove the screw that attaches the top of the passenger-side A-pillar cover to the cab, then remove
the A-pillar cover.

7.3

Remove the two screws from the driver-side A-pillar cover, then pull the bottom of the cover to
loosen the clip that attaches it to the cab structure.

8. Remove the sun visors, as follows:
8.1

Remove the three screws that attach each sun visor to the overhead console. Remove the sun
visors.

8.2

Remove the sun visor inboard retainers.

Freightliner Service Bulletin, 11/03/2017

Page 1

60-157
Freightliner
Service Bulletin

Roof Noise, M2 and 108SD/114SD Day Cabs
FLA COE
FLB COE
FLD Conventional
Business Class
FLC 112 Conventional

Century Class Conventional
Argosy COE
Cargo
Columbia

122SD and Coronado
> Business Class M2
Cascadia
> 108SD/114SD

9. Disconnect the dome light wiring.
10. Remove the coat hooks.
11. Remove the two fir-tree fasteners that attach the center of the headliner to the roof bows.
12. If so equipped, disconnect the air horn lanyard from its anchor point on the headliner and cab roof structure,
then push it up through the slot in the headliner.
13. Remove the four fir-tree fasteners that secure the headliner by the windshield, and the two fir-tree fasteners
at the rear wall.
14. Pull down the headliner, then disconnect the dome light wiring.
15. Remove the headliner from the cab.
16. Cover the seats and dash with a protective drop cloth.
17. Position the new roof bow in place, lining up the holes as shown in Fig. 1, if possible. It may be necessary
to move the roof bow slightly forward, depending on the vehicle options. The roof bow should fit snugly
between the two foam strips inboard of the existing roof bows.

A. Line up the aft holes on the new roof bow with the holes in the existing roof bows.
1. Existing Roof Bow
2. New Roof Bow
Fig. 1, Positioning the New Roof Bow

18. Cut out any insulation (if equipped) from the new roof bow location.
19. Using the bow as template, mark the drilling locations on the existing roof bows.

Page 2

Freightliner Service Bulletin, 11/03/2017

Roof Noise, M2 and 108SD/114SD Day Cabs
FLA COE
FLB COE
FLD Conventional
Business Class
FLC 112 Conventional

Century Class Conventional
Argosy COE
Cargo
Columbia

122SD and Coronado
> Business Class M2
Cascadia
> 108SD/114SD

60-157
Freightliner
Service Bulletin

20. Install a stop collar or a tape stop (see Fig. 2) on a 17/64-inch drill bit to prevent damage to the roof skin.
21. At the four drilling locations, using the 17/64-inch drill bit equipped with the stop collar or tape stop, drill
through the roof bows. Use care not to damage the roof skin. See Fig. 3.

A

08/14/2015

f602558

A. Measurement: 1/2 in (13 mm)
Fig. 2, Making a Tape Stop for the Drill Bit

Fig. 3, Drilling the Holes for the Rivets

22. Using Dow Great Stuff Multipurpose Black Insulating Foam Sealant (see Fig. 4), apply a thick bead in the
two roof-facing grooves of the new bow. See Fig. 5.

Fig. 5, Foam Sealant Applied on Roof Bow
Fig. 4, Dow Great Stuff Multipurpose Black Insulating
Foam Sealant

23. Position the roof bow in place.
24. Using 1/4-inch structural rivets, attach the roof bow in place. See Fig. 6.

Freightliner Service Bulletin, 11/03/2017

Page 3

60-157
Freightliner
Service Bulletin

Roof Noise, M2 and 108SD/114SD Day Cabs
FLA COE
FLB COE
FLD Conventional
Business Class
FLC 112 Conventional

Century Class Conventional
Argosy COE
Cargo
Columbia

122SD and Coronado
> Business Class M2
Cascadia
> 108SD/114SD

Fig. 6, Installing the Rivets

25. Fill in any remaining gaps under the edges of the roof bows.
26. With the help of an assistant, position the headliner in place.
27. Using new fir-tree fasteners, secure the headliner by the windshield and the rear wall.
28. Pull the air horn lanyard out through the slot in the headliner, then attach the lanyard to its anchor point on
the headliner and cab roof structure.
29. Install the sun visors, as follows:
29.1

Install the sun visor inboard retainers.

29.2

Attach the sun visor outboard brackets to the overhead console.

30. Using new fir-tree fasteners, attach the headliner to the roof bows.
31. Attach the center seat belt anchor (if so equipped) to the rear wall.
32. Install the coat hooks.
33. Connect the wiring to the dome light.
34. Install the overhead instrument panel surrounds (if equipped).
35. Install the storage bins (if equipped) in the overhead console.
36. Install the A-pillar covers, as follows:
36.1

Position the driver-side A-pillar cover on the A-pillar, and secure the lower portion by pushing the
fir-tree fastener into the hole on the A-pillar. Secure the upper portion with two screws.

36.2

Position the passenger-side A-pillar cover on the A-pillar, then install a screw through the top hole
into the cab structure.

36.3

Install the passenger-side grab handle on the A-pillar.

37. Install the passenger seat. see the vehicle workshop manual, Group 91.
38. Connect the batteries.

Page 4

Freightliner Service Bulletin, 11/03/2017

Roof Noise, M2 and 108SD/114SD Day Cabs
FLA COE
FLB COE
FLD Conventional
Business Class
FLC 112 Conventional

Century Class Conventional
Argosy COE
Cargo
Columbia

122SD and Coronado
> Business Class M2
Cascadia
> 108SD/114SD

60-157
Freightliner
Service Bulletin

Warranty
This procedure is warrantable only if the described condition exists and the repair is performed within the
applicable base or extended coverage warranty period. If a failure is not found, this procedure is considered
preventive and warranty does not apply.
Normal warranty applies. See Table 2 for OWL VMRS codes and labor allowance information. Enter this service
bulletin number in the Service Bulletin # field.

Primary Failed Part
18-64008-000/-001

OWL VMRS Codes and Labor Allowance
Component
Cause Code SRT Code
Description
Code
ROOF BOW, INSTALL, UNDER ROOF
002-006-001
19
673-5005A
SKIN

Time: Hours
1.5

Table 2, OWL VMRS Codes and Labor Allowance

Freightliner Service Bulletin, 11/03/2017

Page 5