Exhaust Pipe - Rear Section

Remove and replace the rear exhaust pipe section from the muffler to the tailpipe outlet on a 1970 AMC Rebel Machine with 390ci V8 engine.

Warnings

Tools required

Parts

• Rear exhaust pipe section × 1 — Use OEM specification or equivalent aftermarket
• Exhaust clamp kit × 1 — 2.5" diameter clamps typical for 390ci V8
• Exhaust hanger rubber insulators × 2 — Replace as needed

Preparation

1. Park vehicle on level, solid ground and engage parking brake
2. Place wheel chocks in front of and behind front wheels
3. Ensure exhaust system is completely cool to the touch
4. Spray all exhaust clamp bolts and connections with penetrating oil and allow 15-20 minutes to soak
5. Raise rear of vehicle using floor jack at rear axle housing
6. Support vehicle with jack stands under frame rails ahead of rear axle
7. Lower jack slightly to transfer weight to stands and verify stability

Procedure

1. 1

   Inspect exhaust routing and hangers
   From underneath the vehicle, identify the rear exhaust pipe section running from the muffler outlet to the tailpipe exit. Note the location of rubber hanger insulators and clamp connections. The 1970 Rebel Machine typically has two rubber hangers supporting the rear section and uses band clamps at the muffler connection and tailpipe junction.
2. 2

   Support rear pipe section
   Have a helper support the rear exhaust pipe section from behind, or use a temporary support such as a block of wood on a jack positioned under the pipe near the muffler connection. This prevents the pipe from falling when disconnected.
3. 3

   Remove muffler connection clamp
   Locate the band clamp or U-bolt clamp connecting the rear pipe to the muffler outlet. Loosen and remove the clamp nuts or bolts using appropriate wrenches. If bolts are seized, apply additional penetrating oil and allow to soak, or carefully use a hacksaw to cut the clamp if replacement clamps are available.
4. 4

   Separate pipe from muffler
   Twist the rear pipe section while pulling rearward to separate it from the muffler outlet. The connection may be slip-fit or welded. If welded, the pipe will need to be cut approximately 2-3 inches behind the muffler using a pipe cutter or hacksaw. Use a rubber mallet to tap around the joint if the connection is stuck due to carbon buildup.
5. 5

   Disconnect tailpipe or rear clamp
   If the rear section is connected to a separate tailpipe extension, loosen and remove the clamp at this junction. If the rear section extends to the vehicle exit point, proceed to removing hangers. The AMC Rebel Machine rear section typically exits just behind the rear axle on the driver side.
6. 6

   Remove exhaust hanger insulators
   Locate the rubber hanger insulators supporting the rear pipe section. These typically hook onto metal tabs welded to the pipe and corresponding hooks on the vehicle body or frame. Use a twisting and pulling motion to unhook the rubber insulators from the pipe hangers. A spray of soapy water can help the rubber slide off the hooks more easily.
7. 7

   Remove rear exhaust pipe section
   With all clamps and hangers disconnected, carefully lower and remove the rear exhaust pipe section from the vehicle. Maneuver it past the rear axle and suspension components. Note the routing path for installation of the replacement pipe.
8. 8

   Clean connection surfaces
   Use a wire brush to clean the muffler outlet pipe where the new rear section will connect. Remove carbon deposits, rust, and old gasket material to ensure a good seal. If the muffler outlet pipe is damaged or severely corroded, it may need replacement as well.
9. 9

   Inspect and replace rubber hangers
   Examine all rubber hanger insulators for cracks, tears, or deterioration. Replace any damaged hangers to prevent excessive exhaust movement and potential failure. The 1970 AMC typically uses standard oval-style rubber hangers.
10. 10

    Test fit new rear pipe section
    Position the new rear exhaust pipe section into place, routing it along the same path as the original. Verify that it aligns properly with the muffler outlet and tailpipe exit point, and that hanger locations match the vehicle mounting points. Do not fully tighten connections yet.
11. 11

    Install exhaust hangers
    Hook the rubber hanger insulators onto the pipe tabs and vehicle mounting hooks. Ensure hangers are fully seated and supporting the pipe evenly. The pipe should hang with slight clearance from the axle, body panels, and frame components.
12. 12

    Connect and align pipe to muffler
    Slide the front of the rear pipe section onto the muffler outlet, ensuring a minimum 2-inch overlap for slip connections. Position the new exhaust clamp over the joint and hand-tighten the nuts or bolts. Adjust the pipe angle and rotation for proper clearance around the rear axle and to aim the tailpipe exit appropriately.
13. 13

    Final alignment check
    Walk around and view the exhaust from multiple angles. Verify at least 1 inch of clearance between the pipe and all suspension components, fuel tank, body panels, and frame. The tailpipe should exit cleanly without being obstructed. Rock the pipe gently to ensure hangers are secure and alignment is correct.
14. 14

    Tighten all clamps
    Working from front to rear, tighten all exhaust clamps firmly. For band clamps, tighten until the clamp closes evenly and the pipe connection is secure without crushing. For U-bolt clamps, tighten nuts in an alternating pattern. No specific torque specifications are available, so tighten firmly by hand with a wrench until snug, typically 30-35 ft-lbs feel for standard exhaust clamps.

Reassembly

1. Remove jack stands and lower vehicle to the ground
2. Start engine and allow to idle, listening for exhaust leaks at connections
3. If leaks are detected, turn off engine, allow to cool, and re-tighten affected clamps

Verification

• With engine running, feel around clamp connections for escaping exhaust gases indicating leaks
• Listen for unusual rattling or contact sounds that would indicate improper clearance
• Visually inspect from behind the vehicle to ensure tailpipe exit angle is appropriate and not aimed at body panels
• Take a short test drive and re-check all connections and clearances after the exhaust system heat cycles

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