Safety Warning

DIY auto repair can cause serious injury, fire, or vehicle damage. These guides are for informational purposes only. Always follow OEM torque specs, wear PPE, and consult a certified mechanic if you are unsure. You are solely responsible for your safety.

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HOMESERVICE MANUALSGMC1999FORWARD CONTROL 5.7 R, AUTOMATICREPAIR AND DIAGNOSISEXTERNAL PAGESDIFFERENT CARSECTION 633 (ENGINE EXHAUST SYSTEM)REPAIR INSTRUCTIONSMUFFLER REPLACEMENT - LEFTINSTALLATION PROCEDURE

1999 GMC Forward Control 5.7 R, Automatic

Installation Procedure

1999 GMC Forward Control 5.7 R, AutomaticSECTION Installation Procedure

WARNING: This page is about a different car, the 2003 Chevrolet Corvette. However, it is still accessible from the selected car via links, so may be relevant.

NOTE: Refer to EXHAUST SYSTEM INSPECTION NOTICE in Cautions and Notices.

Install the left muffler.
Slide the muffler blade into the hanger.

Fig 1: Left Muffler
Courtesy of GENERAL MOTORS CORP.
Install a NEW exhaust muffler gasket.
NOTE: Refer to FASTENER NOTICE in Cautions and Notices.
Install the left side exhaust muffler bolts.
Tighten

Tighten the exhaust muffler bolts to 50 N.m (37 lb ft).

Fig 2: Left Side Exhaust Muffler Bolts
Courtesy of GENERAL MOTORS CORP.
Position the rear stabilizer shaft upwards.
Install the rear stabilizer shaft insulators and brackets.
Install the rear stabilizer shaft bracket bolts and nuts.
Tighten
- Tighten the rear stabilizer shaft bracket bolts to 65 N.m (49 lb ft).
- Tighten the rear stabilizer shaft bracket nuts to 95 N.m (70 lb ft).
Fig 3: Rear Stabilizer Shaft Bracket Bolts & Nuts
Courtesy of GENERAL MOTORS CORP.

RENDER: 1.0x

NO RELATED

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When to See a Mechanic

Stop DIY work and contact a certified mechanic immediately if any of the following apply:

• You smell fuel, burning insulation, or see smoke.
• Brakes feel soft, pull hard to one side, or make grinding noises.
• The engine overheats, stalls repeatedly, or misfires under load.
• You are missing required tools, torque specs, or safe lifting equipment.
• You are not confident in the next step or safety outcome.