Exhaust Gasket - Rear

This procedure covers replacement of the rear exhaust gasket on a 2014 Ram 2500 with 6.7L Cummins Diesel engine, addressing the connection between the turbocharger downpipe/intermediate pipe and the rear exhaust section.

Warnings

Tools required

Parts

• Rear exhaust flange gasket × 1 — Use OEM specification
• Exhaust flange bolts (if corroded) × 4 — M10 or M12 depending on flange type

Preparation

1. Ensure exhaust system is completely cool to the touch
2. Park vehicle on level surface and engage parking brake
3. Place wheel chocks behind rear wheels
4. Raise vehicle using appropriate lift points or jack and support securely on jack stands
5. Spray penetrating oil on all exhaust flange bolts and hangers at the rear connection point and allow to soak for 15-30 minutes
6. Locate the rear exhaust flange connection (typically between intermediate pipe and rear muffler section under cab area)

Procedure

1. 1

   Support the rear exhaust section
   Position a jack or support under the rear muffler section to prevent the exhaust from dropping when disconnected. This will make reassembly easier and prevent stress on remaining connections.
2. 2

   Remove exhaust hanger connections
   Disconnect the rubber exhaust hangers from their mounting brackets on the rear exhaust section near the flange connection. Use a pry bar or exhaust hanger tool to carefully separate the rubber isolators from the metal hooks. Work the hangers off at an angle to avoid tearing.
   Torque spec

   Hanger Bolts27 Nm (20 lb-ft)
3. 3

   Remove heat shield (if equipped)
   If a heat shield is present covering the flange connection, remove the mounting bolts using appropriate socket. Set heat shield aside for reinstallation.
   Torque spec

   Heat Shield Bolts10 Nm (7 lb-ft)
4. 4

   Remove rear O2 sensor (if equipped at flange)
   If an oxygen sensor is mounted near the rear flange connection, disconnect the electrical connector and remove the sensor using a 22mm oxygen sensor socket or wrench. Be careful not to damage the sensor threads or body.
   ⚠O2 sensors are fragile. Do not use excessive force or the sensor may break off in the exhaust pipe requiring difficult extraction.
   Torque spec

   O2 Sensor45 Nm (33 lb-ft)
5. 5

   Remove exhaust flange bolts
   Remove all bolts securing the rear exhaust flange connection. There are typically 4 bolts connecting the flanges. Start by loosening all bolts 1-2 turns before fully removing any bolt. Support the rear section as you remove the final bolts to prevent it from dropping or binding.
   ⚠If bolts are severely corroded and begin to round off, stop and apply more penetrating oil. Allow additional soak time or use bolt extraction tools as needed.
   Torque spec

   Exhaust Flange Bolts45 Nm (33 lb-ft)
6. 6

   Separate exhaust sections
   Carefully separate the two exhaust sections at the flange. You may need to gently twist or wiggle the pipes to break the seal. Lower the rear section slightly on the support jack and slide it rearward to fully disconnect. Be mindful of remaining hanger connections.
7. 7

   Remove old gasket and clean flange surfaces
   Remove the old exhaust gasket from both flange surfaces. Use a gasket scraper and wire brush to thoroughly clean both mating surfaces, removing all carbon deposits, rust, and old gasket material. Both surfaces must be completely clean and flat for proper sealing. Inspect flanges for warping, cracks, or damage.
8. 8

   Install new exhaust gasket
   Position the new exhaust gasket onto the forward flange (intermediate pipe). Ensure the gasket is centered and aligned with all bolt holes. Some gaskets have an orientation marking - install with any markings facing the correct direction per manufacturer specifications.
9. 9

   Reconnect exhaust sections
   Raise the rear exhaust section using the support jack and align the flange with the forward section. Ensure the new gasket remains properly positioned. Align all bolt holes carefully before inserting any bolts.
10. 10

    Install and torque flange bolts
    Apply anti-seize compound to the threads of all exhaust flange bolts. Insert all bolts and hand-tighten. Tighten bolts in a criss-cross pattern in 2-3 stages to ensure even compression: first to 20 Nm (15 lb-ft), then to final specification of 45 Nm (33 lb-ft). This ensures even gasket compression and prevents flange warping.
    Torque spec

    Exhaust Flange Bolts45 Nm (33 lb-ft)
11. 11

    Reinstall O2 sensor (if removed)
    Apply a thin coat of anti-seize compound to the O2 sensor threads only (do not get anti-seize on the sensor tip). Install the sensor and torque to specification. Reconnect the electrical connector ensuring it clicks securely.
    Torque spec

    O2 Sensor45 Nm (33 lb-ft)
12. 12

    Reinstall heat shield and hangers
    If heat shield was removed, reinstall and torque mounting bolts to specification. Reconnect all rubber exhaust hangers to their mounting brackets. Ensure hangers are fully seated and exhaust is properly supported with adequate clearance from frame, body, and suspension components.
    Torque spec

    Heat Shield Bolts10 Nm (7 lb-ft)

    Hanger Bolts27 Nm (20 lb-ft)
13. 13

    Remove support and verify clearances
    Remove the support jack from under the exhaust. Visually inspect the entire exhaust system to ensure proper alignment and adequate clearance (minimum 1 inch) from all components including frame rails, fuel tank, driveshaft, suspension, and body panels. Adjust hanger positions if needed.

Reassembly

1. Ensure all exhaust hangers are properly connected and exhaust has adequate clearance from all vehicle components
2. Double-check that all flange bolts are torqued to specification in a criss-cross pattern
3. Verify O2 sensor electrical connector is securely attached if sensor was removed

Verification

• Start the engine and listen for exhaust leaks at the rear flange connection. A leak will produce a distinct ticking or hissing sound that increases with engine RPM
• With engine running, carefully feel around the flange connection (without touching hot components) for escaping exhaust gases
• Rev engine to 2000-2500 RPM and listen for any changes in exhaust tone indicating a leak
• After a short test drive, re-inspect the flange connection for signs of leaking (soot stains) and verify all bolts remain tight
• Check that exhaust system does not contact frame, body, or suspension components during normal operation and when articulating suspension

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