TECHNICAL SERVICE BULLETIN
Front End Noise (Clink/Clunk) - Front Differential Mount Frame Bracket
Cracked Or Broken

25-2613
07 January
2026

This bulletin supersedes 24-2408. Reason for update: update the parts list.
Model:
Ford
2021-2024 Bronco

Engine: 2.3L/2.7L

Markets: North American markets only
Issue: Some of the vehicles listed in the Model statement above may exhibit a loud front end clink/clunk noise that
leads to the identification of a cracked or broken front differential frame mount bracket. This may be due to flexing of
the front differential from driving in four wheel drive low (4L) for extended periods of time.
NOTE: Advise the customer that 4L/Rock Crawl drive mode should only be used when necessary, as using
4L when not necessary can cause damage to the vehicle. Refer to the Owner's Manual for additional
information.
Action: For vehicles that meet all of the criteria in the Issue and Model statements, follow the Service Procedure to
repair the mounting bracket using the frame bracket repair service kit and update the AWD module to the latest level
of software using the latest software version of the FDRS scan tool.
Parts
Service Part
Number

Claim
Quantity

Package Order
Quantity

Number in
Package

Description

NB3Z-3D171-P

1

1

1

Front Diff Frame Bracket Kit

W720940-S440

2

1

4

Stabilizer Bar Link Nut

W719869-S439

4

1

4

Stabilizer Bar Undershield Bolt

W721449-S439

2

1

4

Stabilizer Bar Bolt

W520214-S440

2

1

2

Stabilizer Bar Nut

W721041-S439

2

1

4

Stabilizer Bar Stud

JB3Z-4B496-B

6

1

6

Cup Bolt and Retaining Straps

KB3Z-3B477-B

2

1

2

Axle Nut (Vehicles Built On Or After 23Aug-2023)

KB3Z-3B477-A

2

1

2

Axle Nut (Vehicles Built On Or Before
22-Aug-2023)

W717938-S439

4

1

4

Caliper Bracket Bolts

W719491-S439

8

2

4

Hub Bolts (Vehicles Built On Or Before
16-May-2022)

W720861-S439

8

2

4

Hub Bolts (Vehicles Built On Or After
17-May-2022

W716883-S440

2

2

1

Tie Rod Nut

W720110-S440

2

1

4

Lower Ball Joint Nut

W717969-S440

2

1

4

Upper Ball Joint Nut

JB3Z-3B498-A

2

2

1

CV Shaft Retainer

E8UZ-4N282-A

1

1

1

Drain Plug

W500590-S439

1

1

1

Front Axle Mount Bolt

W716126-S442

1

1

1

Axle Extension Bolt and Washer
Assembly

KB3Z-7A443-A

1

1

1

Front Axle Mount Bolt

W717376-S439B

6

2

4

Shield Bolts

Parts - Parts To Inspect And Replace Only If Necessary
Service Part
Number

Claim Quantity

Package Order
Quantity

Number in
Package

MB3Z-5482-B

Only If Necessary
(1 Possible)

Only If Necessary
(1 Possible)

1

NB3Z-5484-A

Only If Necessary
(2 Possible)

Only If Necessary
(2 Possible)

1

MB3Z-4B416A

Only If Necessary
(2 Possible)

Only If Necessary
(2 Possible)

1

YL8Z-4B413AA

Only If Necessary
(1 Possible)

Only If Necessary
(1 Possible)

1

XY-75W85-QL

Only If Necessary

Only If Necessary

Description
Sta-Bar
Sta-Bar Bushing
Axle Seal
Thrust Bearing
Motorcraft® SAE 75W-85 Premium
Synthetic Hypoid Gear Lubricant

Service part numbers and "number in package" quantity may change after publication, thus also affecting the
"package order quantity". Refer to the parts catalog for the latest information.
Claim Quantity refers to the total number of individual pieces required to repair the vehicle.
Package Order Quantity refers to the amount of the service part number package(s) required to repair the vehicle.
Number In Package refers to the number of individual pieces included in a service part number package, also
known as unit of issue (UOI).
As Needed indicates the part is necessary but amount of the part may vary and/or is not a whole number. Parts can
be billed out as non-whole numbers, including less than 1.
Only If Necessary indicates the part is not mandatory. Refer to the Service Procedure to determine the
inspection/inclusion criteria.
Warranty Status: Warranty coverage limits and policies are not altered by a TSB. Warranty coverage limits are
determined by the identified causal part.
Labor Times
Description

Operation
No.

Time

2021-2024 Bronco: Inspect (PASS), Program The AWD Module, Includes Road Test (Do Not
Use With Any Other Labor Operations)

252613A

0.6
Hrs.

2021-2024 Bronco Equipped Without Part Time Engagement: Inspect (FAIL), Repair The
Differential Mount Bracket Following The Service Kit Instructions, Program The AWD Module,
Includes Road Test (Can Be Claimed With Operation F Or G) (Do Not Use With Any Other
Labor Operations Outside Of This Article)

252613B

5.5
Hrs.

2021-2024 Bronco Equipped Without Part Time Engagement And With Sway Bar Disconnect:
Inspect (FAIL), Repair The Differential Mount Bracket Following The Service Kit Instructions,
Program The AWD Module, Includes Road Test (Can Be Claimed With Operation F Or G) (Do
Not Use With Any Other Labor Operations Outside Of This Article)

252613C

6.1
Hrs.

2021-2024 Bronco Equipped With Part Time Engagement: Inspect (FAIL), Repair The
Differential Mount Bracket Following The Service Kit Instructions, Program The AWD Module,
Includes Road Test (Can Be Claimed With Operation F Or G) (Do Not Use With Any Other
Labor Operations Outside Of This Article)

252613D

5.6
Hrs.

2021-2024 Bronco Equipped With Part Time Engagement And With Sway Bar Disconnect:
Inspect (FAIL), Repair The Differential Mount Bracket Following The Service Kit Instructions,
Program The AWD Module, Includes Road Test (Can Be Claimed With Operation F Or G) (Do
Not Use With Any Other Labor Operations Outside Of This Article)

252613E

6.2
Hrs.

Additional Time To Adjust Front Camber And Front Toe (Can Be Claimed With Operation B, C,
D Or E)

252613F

1.1
Hrs.

Additional Time To Adjust Front Camber And Front Toe Equipped With Lane Departure (Can Be
Claimed With Operation B, C, D Or E)

252613G

1.2
Hrs.

Repair/Claim Coding
Causal Part:

3D171

Condition Code: 01

Service Procedure
1. Using a mirror, inspect the front differential frame mount bracket (Figure 1). Is the front differential frame mount
bracket cracked similar to Figure 2?
Figure 1

Figure 2

(1). Yes - proceed to Step 2.
(2). No - proceed to Step 3.
2. Repair the front differential frame mount bracket using the frame bracket repair service kit. Refer to the instruction
sheet provided with the front frame section for installation.
3. Update the AWD module to the latest software level using the latest software version of the FDRS scan tool.

© 2026 Ford Motor Company
All rights reserved.
NOTE: The information in Technical Service Bulletins is intended for use by trained, professional technicians with the knowledge, tools, and
equipment to do the job properly and safely. It informs these technicians of conditions that may occur on some vehicles, or provides information
that could assist in proper vehicle service. The procedures should not be performed by "do-it-yourselfers". Do not assume that a condition
described affects your car or truck. Contact a Ford or Lincoln dealership to determine whether the Bulletin applies to your vehicle. Warranty Policy
and Extended Service Plan documentation determine Warranty and/or Extended Service Plan coverage unless stated otherwise in the TSB article.
The information in this Technical Service Bulletin (TSB) was current at the time of printing. Ford Motor Company reserves the right to supersede
this information with updates. The most recent information is available through Ford Motor Company's on-line technical resources.