Remove and replace the muffler assembly on a 1966 Chevrolet Corvette with 327ci V8 engine, including disconnecting exhaust clamps and reinstalling with proper torque specifications.

Warnings

Tools required

Parts

• Muffler assembly × 1 — Use OEM specification or Walker replacement
• Muffler inlet clamp × 1 — 2.5 inch diameter exhaust clamp
• Muffler outlet clamp × 1 — 2.5 inch diameter exhaust clamp
• Rubber exhaust hangers × 2 — Replace if cracked or deteriorated

Preparation

1. Ensure engine and exhaust system are completely cold to the touch
2. Apply penetrating oil to all muffler clamp bolts and hanger bracket bolts, allowing at least 15 minutes to soak
3. Place wheel chocks behind front wheels
4. Raise rear of vehicle using floor jack positioned on rear crossmember or frame rail
5. Secure vehicle on jack stands positioned under frame rails, ensuring minimum 18 inches of working clearance
6. Visually inspect exhaust system routing and note muffler position and hanger locations

Procedure

1. 1

   Loosen inlet exhaust clamp
   Locate the exhaust clamp connecting the intermediate pipe to the muffler inlet. Using a 15mm socket, loosen the clamp bolt completely but do not remove. If clamp is severely corroded, apply additional penetrating oil and allow to soak for 10 minutes before attempting removal.
2. 2

   Loosen outlet exhaust clamp
   Locate the exhaust clamp connecting the muffler outlet to the tailpipe assembly. Using a 15mm socket, loosen the clamp bolt completely but do not remove. The 1966 Corvette routes exhaust through the rear panel, so the outlet clamp is located near the rear axle.
3. 3

   Remove muffler hanger bracket bolts
   The muffler is supported by 2 rubber hanger insulators attached to frame-mounted brackets. Using a 13mm socket, remove the 2 hanger bracket bolts securing each hanger to the frame. Support the muffler with one hand while removing the final bolt.
4. 4

   Separate muffler from pipes
   Twist the muffler assembly slightly while pulling to separate the inlet connection from the intermediate pipe. You may need to use a rubber mallet to tap the muffler gently if the connection is corroded. Once inlet is free, pull the muffler rearward to disconnect from the outlet tailpipe. Lower the muffler assembly down and remove from under the vehicle.
5. 5

   Clean pipe connection surfaces
   Using a wire brush, clean the outside surface of the intermediate pipe inlet stub and the inside surface of the tailpipe where the muffler connects. Remove all carbon buildup, rust, and old gasket material to ensure proper sealing with the new muffler. Wipe clean with a rag.
6. 6

   Inspect and replace rubber hangers
   Examine both rubber exhaust hanger insulators for cracks, tears, or excessive wear. If rubber is hardened, cracked, or separated from the metal bracket, replace both hangers as a pair to prevent future sagging or rattles.
7. 7

   Position new muffler
   Slide the new muffler inlet over the intermediate pipe stub approximately 2 inches, then align the outlet with the tailpipe inlet. Position the muffler so that hanger brackets align with the frame mounting points. The muffler should sit with adequate clearance from the frame, rear axle, and fuel tank (minimum 1 inch clearance all around).
8. 8

   Install hanger bracket bolts
   Insert the 2 hanger bracket bolts through each rubber hanger and into the frame-mounted threaded holes. Hand-tighten both bolts, ensuring the muffler hangs level and is positioned centrally in the vehicle with equal clearance on both sides. Using a torque wrench and 13mm socket, tighten each hanger bracket bolt to specification.
   Torque spec

   Hanger Bracket Bolts25 Nm (18 lb-ft)
9. 9

   Install and position inlet clamp
   Slide the new inlet clamp over the joint between the intermediate pipe and muffler inlet, ensuring the clamp is centered over the connection with equal overlap on both pipes. Apply a thin coating of anti-seize to the clamp bolt threads if available. Hand-tighten the clamp bolt with a 15mm socket.
10. 10

    Install and position outlet clamp
    Slide the new outlet clamp over the joint between the muffler outlet and tailpipe, ensuring the clamp is centered over the connection. Hand-tighten the clamp bolt with a 15mm socket. Verify the tailpipe exits properly through the rear body panel without contact.
11. 11

    Torque muffler clamps
    Using a torque wrench and 15mm socket, tighten the inlet clamp bolt to specification. Repeat for the outlet clamp bolt. Do not overtighten, as this can collapse the exhaust tubing or crack the clamp.
    Torque spec

    Muffler Clamps55 Nm (41 lb-ft)
12. 12

    Final clearance verification
    Visually inspect the entire muffler assembly and verify minimum 1 inch clearance from all surrounding components including frame rails, rear axle assembly, fuel tank, and body panels. Gently push upward and sideways on the muffler to ensure hangers are secure and clamps are tight with no excessive movement.

Reassembly

1. Lower vehicle from jack stands using floor jack
2. Remove jack stands and lower vehicle completely to ground
3. Remove wheel chocks

Verification

• Start engine and allow to idle, listening for exhaust leaks at both clamp connections (hissing or ticking sounds indicate loose clamps or improper sealing)
• With engine running, visually inspect under vehicle for exhaust smoke escaping from clamp joints
• Rev engine to 2000 RPM briefly and verify no unusual rattles or vibrations from exhaust system
• Take a short test drive and verify no exhaust drone, rattles, or contact sounds from muffler assembly
• After test drive, re-inspect all clamp connections and hanger bolts for tightness while engine is still warm

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