Engine Mount - Rear

Remove and replace the rear engine mount on a 2008 Dodge Viper 8.4L V10, requiring chassis access and engine support to safely detach the mount from the engine block and crossmember.

Warnings

Tools required

Parts

• Rear engine mount assembly × 1 — Mopar 04593932AB or equivalent

Preparation

1. Park vehicle on level, solid surface and engage parking brake. Place wheel chocks at front wheels.
2. Allow engine and exhaust system to cool completely (minimum 2 hours after operation).
3. Disconnect negative battery cable to prevent electrical issues during work.
4. Raise vehicle using floor jack at manufacturer-designated lift points and secure on jack stands at appropriate height for undercarriage access. Verify stability before working underneath.
5. Remove engine undertray/splash shield if equipped to access rear engine mount area.

Procedure

1. 1

   Locate and inspect rear engine mount
   Position yourself under the rear of the engine bay. The rear engine mount is located at the back of the engine block, connecting the engine to the transmission crossmember/rear crossmember. Inspect the mount for the mounting configuration: typically one large through-bolt securing the mount to the engine bracket, and 2-4 fasteners securing the mount to the chassis crossmember. Note any signs of severe deterioration, fluid contamination, or previous damage before proceeding.
2. 2

   Support engine weight
   Position a floor jack with a wood block cushion under the engine oil pan, slightly forward of the rear sump area to avoid the drain plug. Raise the jack until it just contacts the pan with minimal pressure (engine should not lift yet). This provides support before removing mount fasteners. Alternatively, install an engine support bar across the engine bay if chassis clearance is limited. The goal is to take load off the rear mount while maintaining engine alignment.
3. 3

   Remove rear crossmember-to-mount fasteners
   Locate the fasteners securing the lower portion of the rear engine mount to the transmission/rear crossmember. Remove the 3 bolts securing the mount bracket to the crossmember. These are typically 15mm or 18mm head bolts. Apply penetrating oil if fasteners show corrosion. Remove fasteners completely and retain hardware if reusing.
4. 4

   Remove engine-to-mount through-bolt
   Locate the large through-bolt that passes horizontally through the engine bracket and mount assembly. This bolt typically has a 18mm or 21mm head. While supporting the mount with one hand, remove the through-bolt nut and washer from the accessible side. Drive or pull the through-bolt out of the mount assembly. The mount may now hang freely or remain partially captured by the engine bracket.
5. 5

   Raise engine slightly to relieve mount pressure
   Using the floor jack positioned under the oil pan, slowly and carefully raise the engine approximately 0.25 to 0.5 inches. This relieves any remaining compression on the mount and provides clearance for removal. Monitor the engine position and ensure no strain is placed on other mounts, hoses, or wiring. Do not raise excessively as this may stress front engine mounts or accessories.
6. 6

   Remove rear engine mount assembly
   With the engine slightly raised and all fasteners removed, extract the rear engine mount assembly from between the engine bracket and crossmember. The mount may require gentle manipulation or use of a pry bar to break it free from any corrosion or alignment pins. Remove the mount completely from the vehicle and inspect the engine bracket and crossmember mounting surfaces for damage, corrosion, or cracks that would affect new mount installation.
7. 7

   Prepare and position new rear engine mount
   Compare the new rear engine mount to the removed unit to verify correct part and orientation. Clean the engine bracket and crossmember mounting surfaces with a wire brush to remove rust, debris, or old gasket material if present. Position the new mount between the engine bracket and crossmember, aligning the mounting holes. The mount orientation is critical—the rubber isolation element should be positioned to allow engine movement in the designed directions.
8. 8

   Install engine-to-mount through-bolt
   With the new mount positioned, insert the through-bolt through the engine bracket and mount assembly. Install the washer and nut on the accessible side. Hand-tighten the through-bolt nut only at this stage—do not torque yet. The mount should be captured but still able to move slightly for alignment with the crossmember.
9. 9

   Lower engine to load mount and align crossmember holes
   Slowly lower the floor jack to settle the engine weight onto the new rear mount. As the mount compresses under engine weight, the lower mounting holes should align with the crossmember holes. Use a pry bar or drift punch to assist alignment if necessary. Do not force alignment—the engine may need minor repositioning with the jack.
10. 10

    Install crossmember-to-mount fasteners
    Install the 3 bolts securing the mount bracket to the rear crossmember. Start all bolts by hand to ensure threads engage properly. Tighten bolts in a cross-pattern to 45-50 ft-lbs using a torque wrench. This ensures even loading of the mount to the chassis.
11. 11

    Torque engine-to-mount through-bolt
    With the mount now fully constrained to the crossmember and engine weight settled, torque the engine-to-mount through-bolt nut to 55-65 ft-lbs. Hold the bolt head stationary while torquing the nut if possible. This secures the mount to the engine bracket.
12. 12

    Remove engine support and verify installation
    Carefully lower and remove the floor jack from under the engine oil pan. Visually inspect all mount fasteners to ensure they are fully tightened and properly seated. Check that no tools, rags, or hardware have been left in the engine bay. Gently rock the engine by hand (pushing on a solid component like the intake manifold) to verify the mount is holding and allowing normal deflection without binding or excessive movement.

Reassembly

1. Reinstall engine undertray/splash shield if removed, ensuring all fasteners are secured.
2. Reconnect negative battery cable and verify no warning lights appear on instrument cluster.
3. Lower vehicle from jack stands carefully, remove chocks, and perform final walk-around inspection.

Verification

• Start engine and observe for abnormal movement or vibration at idle—rear mount should control engine rocking without excessive deflection.
• With engine running, have an assistant shift transmission through gears (foot on brake) while you observe engine movement from the side—mount should limit movement to normal range without binding.
• Test drive vehicle at low speed and verify no new vibrations, clunks, or abnormal noises are present during acceleration or deceleration.
• Re-inspect all mount fasteners after first 50-100 miles of operation to ensure none have loosened.

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