Aftertreatment Sensor Boss Repair
Replacement of the Aftertreatment Device (ATD) is not necessary if the sensor boss threads are damaged during
service. Detroit™ has released all ATD sensor bosses, along with the required Tungsten Inert Gas (TIG) welding
rods to make repairs.
Note : This repair requires TIG welding and should be done by an experienced welding technician.
Use the tables below to identify the correct sensor boss, hole saw, and arbor needed to make the repair. The
required TIG welding rod part numbers are also provided in Table 1. Either of the two welding rod part numbers
are acceptable for this repair and can be ordered.
To remove the sensor boss, refer to Table 2 to identify the correct size hole saw diameter and part number.
Use the next table to select the correct arbor for the hole saw selected.
Repair as follows:
1. Shut off the engine, apply the parking brake, chock the wheels, and perform any other applicable safety
steps.
CAUTION
ELECTRICAL SHOCK
To avoid injury from electrical shock, use care when connecting battery cables. The magnetic switch
studs are at battery voltage.
2. Disconnect the batteries.
3. Remove the right side fairing. Refer to the Original Equipment Manufacturer (OEM) procedures.
4. Allow the Aftertreatment System (ATS) time to cool.
5. Remove the Aftertreatment from the vehicle.
6. If the sensor boss is shielded as in Figure 1, the heat shield will need to be removed to gain access to the
damaged boss. Figure 2 illustrates a sensor boss not surrounded by a heat shield
7. If needed, use a die grinder to remove the shielding around the damaged sensor boss. The shielding
should be removed as neatly as possible. It will need to be welded back in place once the sensor boss is
replaced.
8. Use the sensor boss to pilot the hole saw. Start cutting the sensor boss weld; check the depth of the cut
frequently to prevent the damaged sensor boss from falling inside the Aftertreatment device. See graphic
below
9. Clean off all metal shavings from around the sensor boss hole; avoid chips from entering the Aftertreatment
device.
10. Verify the new sensor boss fits the sensor before welding in place. Tack weld the sensor boss in place,
then complete the weld around the boss. See graphic below for an example of a newly welded sensor
boss
11. If a section of the heat shield was removed, tack weld the heat shield in place. See graphic below.
12. Once the heat shield is properly tack welded in place, complete the welding.
13. Install the sensor into the new sensor boss. Torque to the correct specification
14. Install the Aftertreatment to the vehicle.
15. Install the right side fairing. Refer to OEM procedures.
16. Connect the batteries.
17. Start the engine.
18. Check for any exhaust leaks.
PERSONAL INJURY
Diesel engine exhaust and some of its constituents are known to the State of California to
cause cancer, birth defects, and other reproductive harm.
PERSONAL INJURY
To avoid injury before starting and running the engine, ensure the vehicle is parked on a
level surface, parking brake is set, and the wheels are blocked
ENGINE EXHAUST
To avoid injury from inhaling engine exhaust, always operate the engine in a well
ventilated area. Engine exhaust is toxic.