Exhaust Hangers

Inspection and replacement of exhaust system rubber hangers and mounting hardware on a 1966 Corvette 327 V8 to restore proper exhaust positioning and eliminate rattles.

Warnings

Tools required

Parts

• Exhaust hanger rubber insulators × 4 — Use OEM specification or aftermarket equivalent
• Exhaust hanger mounting brackets (if corroded) × 1 — Use OEM specification

Preparation

1. Park vehicle on level, solid ground and apply parking brake firmly
2. Place wheel chocks behind rear wheels
3. Allow exhaust system to cool completely (minimum 90 minutes after last engine operation)
4. Raise rear of vehicle using floor jack at rear axle differential housing
5. Support vehicle with jack stands under frame rails just forward of rear axle
6. Lower jack slightly to transfer weight to stands while keeping jack in position as backup support
7. Spray all hanger mounting hardware with penetrating oil and allow to soak for 10 minutes

Procedure

1. 1

   Inspect existing exhaust hangers
   Locate all 4 exhaust hanger points along the exhaust system. On the 1966 Corvette 327 with dual exhaust, inspect each exhaust hanger point per side; verify the exact number and location of hangers against the GM assembly instruction manual before ordering parts, as hanger configuration varies. Visually inspect each rubber insulator for cracks, tears, deterioration, or excessive stretching. Check metal hanger brackets welded to exhaust pipes for rust-through or damage. Note which hangers require replacement.
2. 2

   Support exhaust system at muffler
   Position floor jack with a block of wood on the saddle under the center of the muffler to provide support. Raise jack just enough to contact exhaust without lifting it, preventing the system from dropping when hangers are removed. This is critical as the exhaust system is heavy and can shift unexpectedly.
3. 3

   Remove first muffler hanger
   Starting with the passenger side muffler hanger, use a 9/16" wrench to remove the bolt securing the rubber insulator to the frame bracket. The hanger hook on the muffler will be inserted through the rubber insulator. Use a flat pry bar to carefully pry the rubber insulator off the hanger hook welded to the muffler. Work the insulator side-to-side while prying to avoid tearing it if reusing.
4. 4

   Remove second muffler hanger
   Reposition the jack support to the driver side muffler. Remove the 9/16" bolt from the frame bracket and pry the rubber insulator off the muffler hanger hook using the same technique as the passenger side.
5. 5

   Remove rear tailpipe hangers
   Move to the rear of the vehicle where the tailpipes exit. Each tailpipe has a hanger hook near the exit point. Remove the bolt securing each rubber insulator to the frame-mounted bracket (verify wrench size against actual hardware). Pry each insulator off its respective tailpipe hanger hook. The exhaust system should now be free from all hangers but still supported by the jack.
6. 6

   Clean hanger mounting points
   With hangers removed, use a wire brush to clean rust and debris from the hanger hooks welded to the exhaust pipes and from the frame-mounted bracket bolt holes. Inspect hanger hooks for excessive rust or cracks. If hooks are damaged beyond surface rust, the exhaust component must be replaced or the hook re-welded by a qualified welder.
7. 7

   Install new rear tailpipe hangers
   Starting at the rear, position a new rubber insulator onto the tailpipe hanger hook. The insulator slot must fully seat over the hook. Use a rubber mallet to tap the insulator onto the hook if needed. Align the insulator's mounting hole with the frame bracket and install the hanger-to-bracket bolt finger-tight (verify bolt/wrench size against actual hardware). Repeat for the opposite side tailpipe hanger.
8. 8

   Install new muffler hangers
   Reposition the jack under the passenger side muffler and raise slightly to align the muffler hanger hook with the mounting location. Install a new rubber insulator onto the muffler hanger hook, ensuring it seats fully. Align the insulator with the frame bracket and install the 9/16" bolt finger-tight. Repeat the process for the driver side muffler hanger.
9. 9

   Align exhaust system
   With all hangers installed finger-tight, adjust the position of the exhaust system to ensure proper clearance. The tailpipes should exit evenly and centered in the rear valance openings. Check clearance between exhaust pipes and the frame, floor pan, and rear axle throughout the system. Minimum clearance should be 1 inch at all points. Adjust by shifting the exhaust system within the hanger rubber insulators.
10. 10

    Tighten all hanger bolts
    Once exhaust alignment is verified, tighten all four hanger mounting bolts securely. Tighten the two 1/2" rear tailpipe hanger bolts firmly, then tighten the two 9/16" muffler hanger bolts firmly. Do not overtighten as this can damage the rubber insulators or strip threads in the frame brackets.
11. 11

    Remove jack support
    Carefully lower and remove the floor jack from under the exhaust system. The exhaust should remain in position supported by the hangers with no sagging or misalignment. Visually confirm all hangers are bearing load evenly.

Reassembly

1. Lower vehicle from jack stands carefully
2. Remove jack stands and floor jack
3. Remove wheel chocks

Verification

• Start engine and observe exhaust system while idling. Look for excessive movement, contact with frame or body, or unusual vibrations
• With engine running, have an assistant rev engine to 2500 RPM while you observe exhaust system clearances remain adequate under torque load
• Road test vehicle at various speeds and listen for rattles, clunks, or exhaust contact noises
• After 50 miles of driving, re-inspect all four hanger points to ensure rubber insulators have properly seated and bolts remain tight
• Visually confirm tailpipe exits remain centered and even in rear valance openings

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