SERVICE BULLETIN
CONVENTIONAL CAB STRUCTURE FRONT
MOUNT REPAIR

BULLETIN NO: SB-22-014
DATE: 6-8-2022
REFERENCE: HMM-220601-B1

SUBJECT VEHICLES: 2011MY-2019MY Conventional trucks
equipped with a J08 engine
OVERVIEW:
Depending on vehicle application and operating conditions,
subject vehicles may exhibit cracking around one or both of the
cab structure forward mounts. This might be accompanied with
an audible popping while driving on rough roads. This technical
service bulletin provides instruction for installation of
reinforcement plates to repair a cab with cracking around the
forward mounts.
BEFORE YOU BEGIN:
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Read and understand all instructions before you begin the
work.
Park the vehicle on a flat, level and solid surface.
Place the gear shift lever in "Neutral" or "Park".
Apply the parking brake firmly and confirm parking brake
activation.
Turn off the engine and remove the key from the ignition
switch.
Always wear safety glasses or goggles to protect your eyes.
Place wheel chocks in front of and behind all the wheels to
prevent the vehicle from moving.
Disconnect the battery.

PARTS:
Part Number

Part Description

Quantity

57225EW011

Upper Reinforcement Plate

2

57229EW010

Lower Reinforcement Plate

2

SZ11916023

Bolt/Washer Assembly

2

VEHICLE PREPARATION:
1. Park the vehicle on a flat, level and solid surface. Confirm the
engine is stopped, the ignition switch is in the off (LOCK) position,
and the key is removed.

2. Apply the parking brake.

3. Chock all of the wheels.

INSPECTION:
1. The location for the two potential crack locations are illustrated
below.

2. To inspect, the floor liner will need to be pulled back on both
sides of the vehicle by removing the retaining clips and lifting up
the floor liner. Remove the cab floor plugs to inspect for cracking
around the bolt washers. Driver side is shown below.

3. Example of a crack condition is shown in the photograph
below. If there is no cracking, on both the driver side and the
passenger side, do NOT proceed with this repair.

4. If cracking is identified in one or both sides, BOTH the driver
side and passenger side of the cab floor forward mount channel
will need to be reinforced with weld in place upper and lower
reinforcement plates. Supporting the cab by means of an
overhead hoist will be required throughout this repair procedure.
REPAIR PROCEDURE:
1. Verify the ignition switch is in the off position and disconnect
both battery cables.
NOTICE: Failure to disconnect the battery prior to welding can
damage vehicle control modules.

2. Using an overhead hoist, support the cab at the front corners of
both the door openings on the driver and passenger side to remove
the weight from the forward cab mounting points.
NOTICE: Care needs to be taken to prevent damage to the cab,
doors and related trim.

3. Open the hood and remove the six bolts and one nut securing
the left side fender extension to the cab. Set the fender extension
aside and retain all bolts, nuts, and hardware for reassembly.

4. Remove the retaining clips on the trim piece surrounding the
steering column and on the floor mat below the brake pedal.
Remove the screw securing the throttle pedal stop and the
screws securing the door sill plate to the cab floor. Pull the floor
mat clear of the body mount bolt access hole. Remove the floor
plug.

5. To install the upper reinforcement plate, a small section of the
interior floor pan must be cut out. Care should be taken when
marking and cutting out this section. The section will be welded
back into place once the upper reinforcement plate is installed.

6. Remove the bolt and nut, washers and rubber insulators
securing the cab to the driver side cab mount. Discard the bolt
but retain the nut, washers and insulators for reassembly.

WARNING: The cab must be properly supported by the overhead
hoist before removing the cab mount bracket.
7. Remove the four nuts and bolts securing the drive side cab
mount bracket to the side rail. Retain the bracket, bolts, nuts, and
rubber insulator for reassembly.

WARNING: The cab structure is galvanized. Welding galvanized
material creates toxic fumes. Always weld in a well ventilated
area. Wear a respirator if sufficient ventilation cannot be
achieved.
8. Place a 57725-EW011 upper reinforcement plate over the bolt
hole in the cab floor as shown in the photographs below. Ensure
the reinforcement plate is properly centered. Clean the cab sheet
metal and weld the reinforcement plate to the cab in the areas
highlighted yellow shown below. A bolt and nut can be used to
hold the reinforcement in place if desired during welding.
NOTICE: Ensure the battery is disconnected prior to welding to
avoid damage to vehicle control modules. Utilize welding blankets
to protect nearby components as necessary.
NOTICE: Only certified welders should perform this welding
operation.

WARNING: The cab structure is galvanized. Welding galvanized
material creates toxic fumes. Always weld in a well ventilated
area. Wear a respirator if sufficient ventilation cannot be
achieved.
9. Place a 57229-EW010 lower reinforcement plate on the
underside of the cab as shown in the photographs below. Ensure
the reinforcement plate is properly centered and positioned
correctly. Clean the cab sheet metal and weld the reinforcement
plate to the cab in the areas highlighted yellow shown below. A
bolt and nut can be used to hold the reinforcement in place if
desired during welding.
NOTICE: Ensure the battery is disconnected prior to welding to
avoid damage to vehicle control modules. Utilize welding blankets
to protect nearby wiring and piping.
NOTICE: Only certified welders should perform this welding
operation.

WARNING: The cab structure is galvanized. Welding galvanized
material creates toxic fumes. Always weld in a well ventilated
area. Wear a respirator if sufficient ventilation cannot be
achieved.
10. Weld the interior floor pan section back in the place that was

cut out for access in step 5.

NOTICE: Ensure the battery is disconnected prior to welding to
avoid damage to vehicle control modules. Utilize welding blankets
to protect nearby components as necessary.
NOTICE: Only certified welders should perform this welding
operation.
WARNING: The metal may be hot and could cause burn injuries.
Make sure the metal has cooled before painting.
11. After the metal has cooled, paint the floor pan and cab
underside areas to prevent corrosion.

12. Reinstall the cab mount bracket along with the rubber
insulator to the side rail. Tighten the bolts and nuts to the
specified torque.
Specified Torque: 84 lb-ft (114 Nm)

13. Install a new SZ119-16023 bolt and washer assembly through
the cab and mount assembly along with the nut, washer, and
rubber insulators removed in step 6. Tighten to the specified
torque.
Specified Torque: 162 lb-ft (220 Nm)

14. Reinstall the rubber plug, floor covering, steering column trim,
throttle pedal stop, and door opening trim removed in step 4.

15. Reinstall the fender extension and tighten the fasteners to the
specified torque.
Specified Torque: 16 lb-ft (22 Nm)

16. WARNING: Prior to repeating the repair procedure on the
passenger side, review all Warnings. Repeat the repair
procedure steps 3 through 15 on the passenger side of the
vehicle.
17. Release the overhead hoist supporting the cab.

18. Reconnect the negative battery terminal.

FINAL INSPECTION:
1. To complete this technical service bulletin, review the bulletin
and confirm the following:
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All fasteners that were removed have been reinstalled and
torqued to their specified torque.
Battery connections that were disconnected have a clean
secure connection.
The welded area is correctly welded, and all bare metal
related to this repair has been covered with paint.
The floor plug, floor mat, steering column trim, floor sill plate
and throttle stop have all been positioned correctly and
secured with fasteners.

CLAIM APPLICATION
Hino Base Warranty of 2 Years/Unlimited miles
Reimbursable in accordance within the terms and policies of the
Hino limited warranties.
Cab Structure Forward Mount Repair:
a)
b)
c)
d)
e)

Labor charge: 4.0 Hours
Warranty code: 71112
Trouble code: 51
Operation code: 71250AOT
Original failed part: 9999999999