Exhaust Muffler Replacement 4.3L/4.8L/5.3L/6.0L

Warning: Refer to Protective Goggles and Glove Warning in the Preface section.

Warning: Refer to Exhaust Service Warning in the Preface section.

Note: The muffler is serviced as one complete unit with an exhaust pipe and tail pipe. Some variations of vehicles may have an aftermarket tail pipe added. When the vehicle is raised on the hoist it must be raised by the frame to allow the rear axle to be lowered.

1. Raise the vehicle. Refer to Lifting and Jacking the Vehicle.



2. If equipped with 4.3L engine with a single catalytic converter pipe, remove the nuts retaining the catalytic converter pipe from the muffler flange.



3. If equipped with a 4.8L/5.3L/6.0L engine with dual catalytic converter pipes, loosen the clamp for the right catalytic converter.
4. Remove the nuts retaining the left catalytic converter to the muffler flange.

Note: Depending on the wheel base of the vehicle and the length of the exhaust system the following procedures are required in order to remove the muffler assembly from the vehicle.




5. Remove the muffler assembly hanger pins from the exhaust hanger insulators. Due to the weight of the exhaust system it may take 2 people.
6. Remove the muffler assembly by lifting over the rear axle and remove towards the front of the vehicle.

1. Install the muffler assembly from the front of the vehicle by lifting over the rear axle. Due to the weight of the exhaust system it may take 2 people.
2. Install the muffler assembly hanger pins to the exhaust hanger insulators.

Caution: Refer to Fastener Caution in the Preface section.




3. If equipped with a 4.3L engine, install the retaining nuts and new gasket to the front of the muffler. Tighten the catalytic converter to muffler retaining nuts to 48 N·m (35 lb ft).



4. If equipped with a 4.8L/4.3L/6.0L engine, install the right catalytic converter in the muffler. Tighten the clamp nut to 54 N·m (40 lb ft).
5. Install a new gasket and the nuts retaining the left catalytic converter to the muffler flange.

•	Verify that the exhaust system is properly aligned and tighten the right catalytic converter clamp to 54 N·m (40 lb ft).

•	Tighten the catalytic converter to the muffler flange nuts to 48 N·m (35 lb ft).

6. Lower the vehicle.