Muffler: Service and Repair
MufflerRemoval
All vehicles
WARNING: The normal operating temperature of the exhaust system is very high. Never work around or attempt to repair any part of the exhaust system until it has cooled. Use special care when working around the catalytic converter. The catalytic converter heats to a high temperature after only a short period of engine operation. Failure to follow these instructions may result in personal injury.
CAUTION: Do not use oil or grease-based lubricants on the isolators. These lubricants may cause deterioration of the rubber. This can lead to separation of the isolator from the exhaust hanger bracket during vehicle operation. Use only water-based lubricants on the isolators.
NOTE: Exhaust fasteners are of a prevailing torque design. Use only new fasteners with the same part number as the original. Torque values must be used as specified during reassembly to make sure of correct retention of exhaust components.
1. With the vehicle in NEUTRAL, position it on a hoist. For additional information, refer to Maintenance/Service and Repair
2. Using a suitable jack, support the exhaust system.
4.0L Explorer Sport Trac
3. NOTE: The production muffler assembly is a one-piece design. The service muffler assembly is serviced with 2 pieces.
NOTE: In order to remove the muffler assembly, you must cut the muffler inlet pipe.
Using a suitable exhaust cutter, cut the muffler inlet pipe between the first bend coming out of the muffler and the next bend in line. If a service exhaust coupler is present at this point, loosen the service exhaust coupler nuts and separate the muffler inlet pipe.
^ Discard the service exhaust coupler.
4.6L Explorer Sport Trac
4. NOTE: The production muffler assembly is a one-piece design. The service muffler assembly is serviced with 2 pieces.
NOTE: In order to remove the muffler assembly, you must cut the muffler inlet pipe.
Using a suitable exhaust cutter, cut the muffler inlet pipe between the first bend coming out of the muffler and the next bend in line. If a service exhaust coupler is present at this point, loosen the service exhaust coupler nuts and separate the muffler inlet pipe.
^ Discard the service exhaust coupler.
All vehicles
5. NOTE: When the muffler assembly-to-tailpipe Torca(R) clamp is loosened, a new muffler assembly-to-tailpipe Torca(R) clamp must be installed.
Loosen the muffler assembly-to-tailpipe Torca(R) clamp.
6. Remove the exhaust Y-pipe-dual catalytic converter-to-muffler assembly bolts, nuts and gasket.
^ Discard the exhaust Y-pipe-dual catalytic converter-to-muffler assembly bolts, nuts and gasket.
7. Disconnect the rubber isolators and remove the muffler assembly.
Installation
All vehicles
1. If reusing the tailpipe, install a new muffler assembly-to-tailpipe Torca(R) clamp.
2. Position the muffler assembly and connect the rubber isolators.
3. NOTE: Do not tighten the muffler assembly-to-tailpipe Torca(R) clamp until the exhaust system has been aligned.
NOTE: Using an abrasive pad, clean the muffler assembly-to-tailpipe surface area of any rust.
Position the muffler assembly-to-tailpipe.
Explorer Sport Trac
4. NOTE: Install a new muffler inlet pipe service coupler.
NOTE: Using an abrasive pad, clean the muffler inlet pipe service coupler surface area of any rust.
NOTE: If installing a service muffler kit, the coupling will be welded into position on the muffler inlet pipe.
NOTE: The factory muffler inlet pipe will not have an alignment nub.
If reusing the factory muffler assembly, position the 2 halves of the muffler inlet pipe into the service exhaust coupler and center the service exhaust coupler onto the cut joint on the muffler inlet pipe. If installing a new service muffler kit, install the muffler inlet pipe coming out of the muffler into the service exhaust coupler.
All Vehicles
5. NOTE: Install new exhaust Y-pipe-dual catalytic converter-to-muffler assembly gasket, bolts and nuts.
Loosely install the exhaust Y-pipe-dual catalytic converter-to-muffler assembly gasket, bolts and nuts.
6. Align the exhaust system.