Exhaust System Alignment. Buick Roadmaster 1996

For 1990-2009 cars

1. Raise and suitably support the vehicle. Refer to General Vehicle Lifting and Jacking in General Information.
2. Loosen the converter nuts, but do not remove the converter nuts.
3. Loosen the muffler screws, but do not remove the muffler screws.
4. Loosen the four converter support bolts that attach the support to the converter, and the support to the support bracket on the intermediate pipe (for the 5.7L LT1 engine) or the left-leg of the crossover pipe (for the Chevrolet with 4.3L L99 engine).
5. Loosen the converter support bracket clamp nut, until the bracket clamp can slide onto the left-hand intermediate pipe (for the 5.7L LT1 engine), or on the left-leg of the crossover pipe (for the Chevrolet with 4.3L L99 engine). Do not remove the converter support bracket clamp nut.
6. Loosen the muffler clamp nuts, until the clamp can slide onto the muffler outlet. Repeat for the other side, if equipped.

Tighten

• | Tighten the converter nuts to 50 N·m (37 lb ft).

• | Tighten only the two converter support bolts that secure the dampener to the support and the converter, to 34 N·m (25 lb ft). Ensure that the bottom edge of the dampener is horizontal.

Notice: Use the correct fastener in the correct location. Replacement fasteners must be the correct part number for that application. Fasteners requiring replacement or fasteners requiring the use of thread locking compound or sealant are identified in the service procedure. Do not use paints, lubricants, or corrosion inhibitors on fasteners or fastener joint surfaces unless specified. These coatings affect fastener torque and joint clamping force and may damage the fastener. Use the correct tightening sequence and specifications when installing fasteners in order to avoid damage to parts and systems.

7. Tap the muffler clamp toward the rear of the vehicle, in order to contact the resonator tab (right-hand only for Chevrolet with 4.3L L99 engine) (both right- and left-hand for 5.7L LT1 engine).

Tighten

• | Tighten the muffler clamp nuts to 35 N·m (26 lb ft). Ensure that the clamp U-bolts are positioned with the threaded ends pointed outboard.

• | Tighten the muffler bolts to 20 N·m (15 lb ft).

8. Position the converter support bracket (on the left leg of the crossover pipe on the Chevrolet with 4.3L L99 engine, or the left-hand intermediate pipe on the 5.7L LT1 engine) to the front face of the converter support.

Tighten

• | Tighten the remaining two converter support bolts, that secure the support bracket to the support, to 34 N·m (25 lb ft).

• | Tighten the support bracket clamp nut to 35 N·m (26 lb ft).

9. Lower the vehicle.