Fifth Wheel Outboard Angle Mount Fastener Change
Constellation
Heritage
> 5700 Models
> 4800 Models

31-013
Western Star
Service Bulletin

> 4900 Models
> 4700 Models
6900 Models

General Information
With the start of production on March 6, 2018, the fasteners used to attach the slide- and plate-mount style fifth
wheels to the outboard angles changed to M16 metric bolts, nuts, and washers. This change also includes a
revision to a higher friction nut which requires an increase in tightening torque. The new higher friction nut can
be identified by its blue color (Fig. 1). Blue fasteners are metric. If the fifth wheel mounting hardware is being
removed replace with new hardware per the part numbers in PartsPro. See Fig. 2.
Tighten the fifth wheel M16 fasteners from the bolt head to 170 ± 12 lbf·ft (230 ± 16 N·m).

NOTE: The higher friction nut can be identified by its
blue color.
Fig. 1, New High Friction Nut

Fig. 2, Fifth Wheel Mounting Fasteners

The new fasteners are available from the PDC’s. See Table 1.

Part Number
23-14283-L*
23-14451-116
23-09114-000

Replacement Fasteners
Description
BOLT-HEX,PC10.9,PO,M16
NUT-HEX,LKG,ZNAL,M16X1.5
WASHER-HRDN,0.69X1.31X.177

Qty
as required
as required
as required

* The bolt length "L" is determined by the last 3 digits of the part number. Example: 23-14283-060 is 60 mm long.

Table 1, Replacement Fasteners

WARNING
All fifth wheel maintenance, adjustment, and rebuilding must be done only by a qualified mechanic.
Improper or incomplete procedures could result in disengagement of the trailer from the tractor, leading
to personal injury or property damage.

Western Star Service Bulletin, 05/03/2018

Page 1

31-013

Fifth Wheel Outboard Angle Mount Fastener Change

Western Star
Service Bulletin

Constellation
Heritage
> 5700 Models
> 4800 Models

> 4900 Models
> 4700 Models
6900 Models

NOTE: A frame fastener torque check is required at Initial Maintenance and periodically there after.
See the vehicle Maintenance Manual, Group 31.

Warranty
This is an information bulletin only. Warranty does not apply.

Page 2

Western Star Service Bulletin, 05/03/2018